ASTM D7578-20
(Guide)Standard Guide for Calibration Requirements for Elemental Analysis of Petroleum Products and Lubricants
Standard Guide for Calibration Requirements for Elemental Analysis of Petroleum Products and Lubricants
SIGNIFICANCE AND USE
5.1 Crude oil, petroleum, petroleum products, additives, biofuels, and lubricants are routinely analyzed for their elemental content such as chlorine, nitrogen, hydrogen, phosphorus, sulfur, and various metals using a variety of analytical techniques. Some of these methods require little to no method calibration; some others require only simple one step calibration; while others require elaborate calibration routine before the product is analyzed for its elemental content.
5.2 Fairly often it can be shown that the round robin results by a co-operator are all biased with respect to those from other laboratories. Presumably, the failure to follow good laboratory practices and instructions in the test methods can be a causal factor of such errors. A further consequence is an unnecessarily large reproducibility estimate or the data being dropped from the study as an outlier.
5.2.1 Another cause of such discrepancies could be different or inadequate calibration practice used in the laboratory. Most test methods spell out the calibration requirements but often do not quote the frequency required letting the laboratories use good laboratory practices for this task. Thus, uniform practice for instrument calibration would be beneficial in standardizing the test procedures and obtaining consistent results across the laboratories.
5.3 Committee D02 has already issued standard practices for uniform sample preparation (D7455), standard operating procedures for ICP-AES (D7260) and XRF (D7343) as well as standard quality assurance protocol (D6792). This guide should be considered as a continuing effort on behalf of this subcommittee to achieve standardized practices in all parts of an analytical sequence.
SCOPE
1.1 This guide covers different ways by which the test methods used for elemental analysis of petroleum product and lubricant samples are calibrated before the sample analysis.
1.2 Uniform practice for test method calibration is beneficial in standardizing the procedures, and obtaining consistent results across different laboratories.
1.3 This guide includes only the basic steps for generally encountered instrument types. Anything out of the ordinary may require special procedures. See individual test methods for instructions to handle such situations.
1.4 This guide is not a substitute for a thorough understanding of the actual test method to be used, caveats it contains, and additional instrument preparation that may be required.
1.5 The user should not expand the scope of the test methods to materials or concentrations outside the scope of the test methods being used.
1.6 This guide should also be applicable to sample preparation of non-petroleum based bio-fuels for elemental analysis. Work is underway on these aspects in Subcommittee D02.03. As more information becomes available, it will be added to this standard.
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
- Status
- Published
- Publication Date
- 30-Apr-2020
- Technical Committee
- D02 - Petroleum Products, Liquid Fuels, and Lubricants
- Drafting Committee
- D02.03 - Elemental Analysis
Relations
- Effective Date
- 01-May-2020
- Effective Date
- 01-Apr-2024
- Effective Date
- 01-Mar-2024
- Effective Date
- 01-Mar-2024
- Effective Date
- 01-Nov-2023
- Effective Date
- 01-Nov-2023
- Effective Date
- 01-Oct-2023
- Effective Date
- 01-Oct-2023
- Effective Date
- 01-Jul-2020
- Effective Date
- 01-May-2020
- Effective Date
- 01-May-2020
- Effective Date
- 01-May-2020
- Effective Date
- 01-May-2020
- Effective Date
- 01-May-2020
- Effective Date
- 01-Jul-2019
Overview
ASTM D7578-20: Standard Guide for Calibration Requirements for Elemental Analysis of Petroleum Products and Lubricants provides essential guidance for laboratories conducting elemental analysis on petroleum products, lubricants, biofuels, and related materials. Accurate elemental analysis-covering components like sulfur, chlorine, nitrogen, phosphorus, and various metals-is critical for quality assurance, regulatory compliance, and process optimization within the oil and gas and lubricants industries. Uniform calibration practices are necessary to ensure results are reliable, reproducible, and accepted across multiple laboratories.
Key Topics
- Calibration Practices: The standard outlines the fundamental requirements for calibration of analytical instruments used in elemental analysis. These range from simple verification routines for basic laboratory apparatus to complex, multi-step calibrations for sophisticated instruments.
- Reference Materials & Traceability: Emphasis is placed on selecting appropriate certified reference materials (CRMs) and calibration standards that are traceable to national or international standards, ideally validated by authoritative bodies like NIST.
- Frequency & Documentation: ASTM D7578-20 stresses the need for clear calibration schedules, proper maintenance of calibration records (manual or electronic), and adherence to both manufacturer guidance and laboratory experience.
- Uniformity Across Laboratories: The guide addresses the common challenge of inter-laboratory biases and inconsistencies, advocating for standardized calibration processes to improve data accuracy, reproducibility, and acceptance in collaborative and multi-site studies.
- Types of Analytical Instruments: The document provides a classification of laboratory equipment by the extent of calibration required-from minimal (e.g., glassware, simple mixers) to extensive (e.g., ICP-AES, XRF, AAS).
- Quality Control & Verification: The distinction between calibration and verification is clarified, and laboratories are urged to routinely monitor performance, apply corrective actions, and participate in inter-laboratory comparisons when required.
Applications
Adhering to ASTM D7578-20 offers practical benefits for laboratories and industries involved in:
- Routine Elemental Analysis: Ensures consistent calibration for methods determining sulfur, phosphorus, chlorine, metals, and other elements in crude oil, fuels, lubricants, additives, and biofuels.
- Quality Assurance Programs: Supports comprehensive QA/QC protocols by providing frameworks for using reference materials and documentation to guarantee data integrity.
- Inter-Laboratory Studies: Facilitates reliable comparison of data across laboratories by harmonizing calibration procedures and minimizing systematic errors and outliers.
- Regulatory Compliance: Assists in meeting national and international testing and reporting requirements for petroleum products and lubricants, underlining traceability and documentation.
- Instrument Maintenance: Guides laboratories in the maintenance and calibration of a variety of analytical equipment, from balances and thermometers to advanced spectrometry systems like ICP-AES and XRF.
- Biofuel Analysis: As the standard is updated, its coverage of biofuel calibration requirements will continue to grow, promoting standardized methodologies for emerging energy sources.
Related Standards
ASTM D7578-20 references and complements a range of important standards, including:
- ASTM D7455: Practice for Sample Preparation of Petroleum and Lubricant Products for Elemental Analysis
- ASTM D7260: Practice for Optimization, Calibration, and Validation of ICP-AES for Elemental Analysis
- ASTM D7343: Practice for XRF Spectrometry Methods in Petroleum Products and Lubricants Analysis
- ASTM D6792: Practice for Quality Management Systems in Petroleum Product Testing Laboratories
- NIST Special Publications: Guidance on value-assignment of reference materials for chemical measurements
- ISO Guide 30: Terms and definitions for reference materials
Additional referenced standards cover specific elemental test methods for sulfur, chlorine, phosphorus, and various metals using techniques such as atomic absorption, X-ray fluorescence, and ICP-AES.
By following ASTM D7578-20, laboratories strengthen measurement reliability and foster broader acceptance of their test results-an essential component for quality control, industrial certification, and regulatory submissions in the petroleum and lubricants sector.
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Frequently Asked Questions
ASTM D7578-20 is a guide published by ASTM International. Its full title is "Standard Guide for Calibration Requirements for Elemental Analysis of Petroleum Products and Lubricants". This standard covers: SIGNIFICANCE AND USE 5.1 Crude oil, petroleum, petroleum products, additives, biofuels, and lubricants are routinely analyzed for their elemental content such as chlorine, nitrogen, hydrogen, phosphorus, sulfur, and various metals using a variety of analytical techniques. Some of these methods require little to no method calibration; some others require only simple one step calibration; while others require elaborate calibration routine before the product is analyzed for its elemental content. 5.2 Fairly often it can be shown that the round robin results by a co-operator are all biased with respect to those from other laboratories. Presumably, the failure to follow good laboratory practices and instructions in the test methods can be a causal factor of such errors. A further consequence is an unnecessarily large reproducibility estimate or the data being dropped from the study as an outlier. 5.2.1 Another cause of such discrepancies could be different or inadequate calibration practice used in the laboratory. Most test methods spell out the calibration requirements but often do not quote the frequency required letting the laboratories use good laboratory practices for this task. Thus, uniform practice for instrument calibration would be beneficial in standardizing the test procedures and obtaining consistent results across the laboratories. 5.3 Committee D02 has already issued standard practices for uniform sample preparation (D7455), standard operating procedures for ICP-AES (D7260) and XRF (D7343) as well as standard quality assurance protocol (D6792). This guide should be considered as a continuing effort on behalf of this subcommittee to achieve standardized practices in all parts of an analytical sequence. SCOPE 1.1 This guide covers different ways by which the test methods used for elemental analysis of petroleum product and lubricant samples are calibrated before the sample analysis. 1.2 Uniform practice for test method calibration is beneficial in standardizing the procedures, and obtaining consistent results across different laboratories. 1.3 This guide includes only the basic steps for generally encountered instrument types. Anything out of the ordinary may require special procedures. See individual test methods for instructions to handle such situations. 1.4 This guide is not a substitute for a thorough understanding of the actual test method to be used, caveats it contains, and additional instrument preparation that may be required. 1.5 The user should not expand the scope of the test methods to materials or concentrations outside the scope of the test methods being used. 1.6 This guide should also be applicable to sample preparation of non-petroleum based bio-fuels for elemental analysis. Work is underway on these aspects in Subcommittee D02.03. As more information becomes available, it will be added to this standard. 1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
SIGNIFICANCE AND USE 5.1 Crude oil, petroleum, petroleum products, additives, biofuels, and lubricants are routinely analyzed for their elemental content such as chlorine, nitrogen, hydrogen, phosphorus, sulfur, and various metals using a variety of analytical techniques. Some of these methods require little to no method calibration; some others require only simple one step calibration; while others require elaborate calibration routine before the product is analyzed for its elemental content. 5.2 Fairly often it can be shown that the round robin results by a co-operator are all biased with respect to those from other laboratories. Presumably, the failure to follow good laboratory practices and instructions in the test methods can be a causal factor of such errors. A further consequence is an unnecessarily large reproducibility estimate or the data being dropped from the study as an outlier. 5.2.1 Another cause of such discrepancies could be different or inadequate calibration practice used in the laboratory. Most test methods spell out the calibration requirements but often do not quote the frequency required letting the laboratories use good laboratory practices for this task. Thus, uniform practice for instrument calibration would be beneficial in standardizing the test procedures and obtaining consistent results across the laboratories. 5.3 Committee D02 has already issued standard practices for uniform sample preparation (D7455), standard operating procedures for ICP-AES (D7260) and XRF (D7343) as well as standard quality assurance protocol (D6792). This guide should be considered as a continuing effort on behalf of this subcommittee to achieve standardized practices in all parts of an analytical sequence. SCOPE 1.1 This guide covers different ways by which the test methods used for elemental analysis of petroleum product and lubricant samples are calibrated before the sample analysis. 1.2 Uniform practice for test method calibration is beneficial in standardizing the procedures, and obtaining consistent results across different laboratories. 1.3 This guide includes only the basic steps for generally encountered instrument types. Anything out of the ordinary may require special procedures. See individual test methods for instructions to handle such situations. 1.4 This guide is not a substitute for a thorough understanding of the actual test method to be used, caveats it contains, and additional instrument preparation that may be required. 1.5 The user should not expand the scope of the test methods to materials or concentrations outside the scope of the test methods being used. 1.6 This guide should also be applicable to sample preparation of non-petroleum based bio-fuels for elemental analysis. Work is underway on these aspects in Subcommittee D02.03. As more information becomes available, it will be added to this standard. 1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
ASTM D7578-20 is classified under the following ICS (International Classification for Standards) categories: 75.080 - Petroleum products in general; 75.100 - Lubricants, industrial oils and related products. The ICS classification helps identify the subject area and facilitates finding related standards.
ASTM D7578-20 has the following relationships with other standards: It is inter standard links to ASTM D7578-18, ASTM D445-24, ASTM D3231-24, ASTM D6481-24, ASTM D445-23, ASTM D6792-23c, ASTM D6792-23b, ASTM D892-23, ASTM D7740-20, ASTM D7040-04(2020), ASTM D6470-99(2020), ASTM D7171-20, ASTM E898-20, ASTM D6732-04(2020), ASTM D5453-19a. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
ASTM D7578-20 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D7578 − 20
Standard Guide for
Calibration Requirements for Elemental Analysis of
Petroleum Products and Lubricants
This standard is issued under the fixed designation D7578; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
1.1 This guide covers different ways by which the test
Barriers to Trade (TBT) Committee.
methods used for elemental analysis of petroleum product and
lubricant samples are calibrated before the sample analysis.
2. Referenced Documents
1.2 Uniform practice for test method calibration is benefi-
2.1 ASTM Standards:
cial in standardizing the procedures, and obtaining consistent
D129 Test Method for Sulfur in Petroleum Products (Gen-
results across different laboratories.
eral High Pressure Decomposition Device Method)
D445 Test Method for Kinematic Viscosity of Transparent
1.3 This guide includes only the basic steps for generally
and Opaque Liquids (and Calculation of Dynamic Viscos-
encountered instrument types. Anything out of the ordinary
ity)
mayrequirespecialprocedures.Seeindividualtestmethodsfor
D482 Test Method for Ash from Petroleum Products
instructions to handle such situations.
D808 Test Method for Chlorine in New and Used Petroleum
1.4 This guide is not a substitute for a thorough understand-
Products (High Pressure Decomposition Device Method)
ingoftheactualtestmethodtobeused,caveatsitcontains,and
D874 Test Method for Sulfated Ash from Lubricating Oils
additional instrument preparation that may be required.
and Additives
1.5 The user should not expand the scope of the test
D892 Test Method for Foaming Characteristics of Lubricat-
methods to materials or concentrations outside the scope of the
ing Oils
test methods being used.
D1018 Test Method for Hydrogen In Petroleum Fractions
D1091 Test Methods for Phosphorus in Lubricating Oils and
1.6 This guide should also be applicable to sample prepa-
Additives
ration of non-petroleum based bio-fuels for elemental analysis.
D1266 Test Method for Sulfur in Petroleum Products (Lamp
Work is underway on these aspects in Subcommittee D02.03.
Method)
Asmoreinformationbecomesavailable,itwillbeaddedtothis
D1318 Test Method for Sodium in Residual Fuel Oil (Flame
standard.
Photometric Method)
1.7 The values stated in SI units are to be regarded as
D1548 Test Method for Vanadium in Heavy Fuel Oil
standard. No other units of measurement are included in this
(Withdrawn 1997)
standard.
D1552 Test Method for Sulfur in Petroleum Products by
1.8 This standard does not purport to address all of the
High Temperature Combustion and Infrared (IR) Detec-
safety concerns, if any, associated with its use. It is the
tion or Thermal Conductivity Detection (TCD)
responsibility of the user of this standard to establish appro-
D1839 Test Method forAmyl Nitrate in Diesel Fuels (With-
priate safety, health, and environmental practices and deter-
drawn 2019)
mine the applicability of regulatory limitations prior to use.
D2622 Test Method for Sulfur in Petroleum Products by
1.9 This international standard was developed in accor-
Wavelength Dispersive X-ray Fluorescence Spectrometry
dance with internationally recognized principles on standard-
D2784 Standard Test Method for Sulfur in Liquefied Petro-
ization established in the Decision on Principles for the
leum Gases (Oxy-Hydrogen Burner or Lamp) (Withdrawn
2016)
1 2
This guide is under the jurisdiction of ASTM Committee D02 on Petroleum For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom- contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
mittee D02.03 on Elemental Analysis. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved May 1, 2020. Published June 2020. Originally the ASTM website.
approved in 2010. Last previous edition approved in 2018 as D7578 – 18. DOI: The last approved version of this historical standard is referenced on
10.1520/D7578-20. www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7578 − 20
D3120 Test Method for Trace Quantities of Sulfur in Light D5185 Test Method for Multielement Determination of
Liquid Petroleum Hydrocarbons by Oxidative Microcou- Used and Unused Lubricating Oils and Base Oils by
lometry Inductively Coupled Plasma Atomic Emission Spectrom-
etry (ICP-AES)
D3228 Test Method for Total Nitrogen in Lubricating Oils
D5291 Test Methods for Instrumental Determination of
and Fuel Oils by Modified Kjeldahl Method
Carbon, Hydrogen, and Nitrogen in Petroleum Products
D3230 Test Method for Salts in Crude Oil (Electrometric
and Lubricants
Method)
D5384 Test Methods for Chlorine in Used Petroleum Prod-
D3231 Test Method for Phosphorus in Gasoline
ucts (Field Test Kit Method)
D3237 TestMethodforLeadinGasolinebyAtomicAbsorp-
D5453 Test Method for Determination of Total Sulfur in
tion Spectroscopy
Light Hydrocarbons, Spark Ignition Engine Fuel, Diesel
D3246 Test Method for Sulfur in Petroleum Gas by Oxida-
Engine Fuel, and Engine Oil by Ultraviolet Fluorescence
tive Microcoulometry
D5600 Test Method for Trace Metals in Petroleum Coke by
D3340 Test Method for Lithium and Sodium in Lubricating
Inductively Coupled Plasma Atomic Emission Spectrom-
Greases by Flame Photometer (Withdrawn 2013)
etry (ICP-AES)
D3341 Test Method for Lead in Gasoline—Iodine Mono-
D5622 Test Methods for Determination of Total Oxygen in
chloride Method
Gasoline and Methanol Fuels by Reductive Pyrolysis
D3348 Test Method for Rapid Field Test for Trace Lead in
D5708 Test Methods for Determination of Nickel,
Unleaded Gasoline (Colorimetric Method)
Vanadium, and Iron in Crude Oils and Residual Fuels by
D3605 Test Method for Trace Metals in Gas Turbine Fuels
Inductively Coupled Plasma (ICP) Atomic Emission
by Atomic Absorption and Flame Emission Spectroscopy
Spectrometry
D3831 Test Method for Manganese in Gasoline By Atomic
D5762 Test Method for Nitrogen in Liquid Hydrocarbons,
Absorption Spectroscopy
Petroleum and Petroleum Products by Boat-Inlet Chemi-
D4045 Test Method for Sulfur in Petroleum Products by
luminescence
Hydrogenolysis and Rateometric Colorimetry
D5800 Test Method for Evaporation Loss of Lubricating
D4046 Test Method for Alkyl Nitrate in Diesel Fuels by
Oils by the Noack Method
Spectrophotometry (Withdrawn 2019)
D5863 Test Methods for Determination of Nickel,
D4047 Test Method for Phosphorus in Lubricating Oils and
Vanadium, Iron, and Sodium in Crude Oils and Residual
Additives by Quinoline Phosphomolybdate Method
Fuels by Flame Atomic Absorption Spectrometry
D4294 Test Method for Sulfur in Petroleum and Petroleum
D6334 Test Method for Sulfur in Gasoline by Wavelength
Products by Energy Dispersive X-ray Fluorescence Spec-
Dispersive X-Ray Fluorescence
trometry
D6443 TestMethodforDeterminationofCalcium,Chlorine,
D4307 Practice for Preparation of Liquid Blends for Use as
Copper, Magnesium, Phosphorus, Sulfur, and Zinc in
Analytical Standards
Unused Lubricating Oils and Additives by Wavelength
D4628 Test Method for Analysis of Barium, Calcium,
Dispersive X-ray Fluorescence Spectrometry (Mathemati-
Magnesium, and Zinc in Unused Lubricating Oils by
cal Correction Procedure)
Atomic Absorption Spectrometry
D6445 Test Method for Sulfur in Gasoline by Energy-
D4629 Test Method for Trace Nitrogen in Liquid Hydrocar-
Dispersive X-ray Fluorescence Spectrometry (Withdrawn
bons by Syringe/Inlet Oxidative Combustion and Chemi- 3
2009)
luminescence Detection
D6470 Test Method for Salt in Crude Oils (Potentiometric
D4927 Test Methods for Elemental Analysis of Lubricant
Method)
and Additive Components—Barium, Calcium,
D6481 Test Method for Determination of Phosphorus,
Phosphorus, Sulfur, and Zinc by Wavelength-Dispersive
Sulfur, Calcium, and Zinc in Lubrication Oils by Energy
X-Ray Fluorescence Spectroscopy
Dispersive X-ray Fluorescence Spectroscopy
D4929 Test Method for Determination of Organic Chloride
D6595 Test Method for Determination of Wear Metals and
Content in Crude Oil
Contaminants in Used Lubricating Oils or Used Hydraulic
D4951 Test Method for Determination ofAdditive Elements
Fluids by Rotating Disc ElectrodeAtomic Emission Spec-
in Lubricating Oils by Inductively Coupled Plasma
trometry
Atomic Emission Spectrometry
D6667 Test Method for Determination of Total Volatile
D5056 Test Method for Trace Metals in Petroleum Coke by
Sulfur in Gaseous Hydrocarbons and Liquefied Petroleum
Atomic Absorption
Gases by Ultraviolet Fluorescence
D5059 Test Methods for Lead and Manganese in Gasoline
D6728 Test Method for Determination of Contaminants in
by X-Ray Spectroscopy
Gas Turbine and Diesel Engine Fuel by Rotating Disc
D5184 Test Methods for Determination of Aluminum and
Electrode Atomic Emission Spectrometry
Silicon in Fuel Oils by Ashing, Fusion, Inductively
D6732 Test Method for Determination of Copper in Jet
Coupled Plasma Atomic Emission Spectrometry, and Fuels by Graphite Furnace Atomic Absorption Spectrom-
Atomic Absorption Spectrometry etry
D7578 − 20
D6792 Practice for Quality Management Systems in Petro- D7623 Test Method for Total Mercury in Crude Oil Using
leum Products, Liquid Fuels, and Lubricants Testing Combustion-Gold Amalgamation and Cold Vapor Atomic
Absorption Method
Laboratories
D7691 TestMethodforMultielementAnalysisofCrudeOils
D6920 Test Method forTotal Sulfur in Naphthas, Distillates,
Using Inductively Coupled Plasma Atomic Emission
Reformulated Gasolines, Diesels, Biodiesels, and Motor
Spectrometry (ICP-AES)
Fuels by Oxidative Combustion and Electrochemical De-
D7740 Practice for Optimization, Calibration, and Valida-
tection (Withdrawn 2018)
tion ofAtomicAbsorption Spectrometry for MetalAnaly-
D7039 Test Method for Sulfur in Gasoline, Diesel Fuel, Jet
sis of Petroleum Products and Lubricants
Fuel, Kerosine, Biodiesel, Biodiesel Blends, and
D7751 Test Method for Determination ofAdditive Elements
Gasoline-Ethanol Blends by Monochromatic Wavelength
in Lubricating Oils by EDXRF Analysis
Dispersive X-ray Fluorescence Spectrometry
D7757 Test Method for Silicon in Gasoline and Related
D7040 Test Method for Determination of Low Levels of
Products by Monochromatic Wavelength Dispersive
Phosphorus in ILSAC GF 4 and Similar Grade Engine
X-ray Fluorescence Spectrometry
Oils by Inductively Coupled Plasma Atomic Emission
D8110 Test Method for Elemental Analysis of Distillate
Spectrometry
Products by Inductively Coupled Plasma Mass Spectrom-
D7041 Test Method for Determination of Total Sulfur in
etry (ICP-MS)
Liquid Hydrocarbons and Hydrocarbon-Oxygenate
D8127 Test Method for Coupled Particulate and Elemental
Blends by Gas Chromatography with Flame Photometric
Analysis using X-ray Fluorescence (XRF) for In-Service
Detection
Lubricants
D7111 Test Method for Determination of Trace Elements in
D8150 Test Method for Determination of Organic Chloride
Middle Distillate Fuels by Inductively Coupled Plasma
Content in Crude Oil by Distillation Followed by Detec-
Atomic Emission Spectrometry (ICP-AES)
tion Using Combustion Ion Chromatography
D7171 Test Method for Hydrogen Content of Middle Dis-
E77 Test Method for Inspection and Verification of Ther-
tillate Petroleum Products by Low-Resolution Pulsed
mometers
Nuclear Magnetic Resonance Spectroscopy
E319 Practice for the Evaluation of Single-Pan Mechanical
D7212 Test Method for Low Sulfur inAutomotive Fuels by
Balances
Energy-Dispersive X-ray Fluorescence Spectrometry Us-
E898 Test Method of Testing Top-Loading, Direct-Reading
ing a Low-Background Proportional Counter
Laboratory Scales and Balances
D7220 Test Method for Sulfur in Automotive, Heating, and
2.2 NIST Standard:
Jet Fuels by Monochromatic Energy Dispersive X-ray
NIST Special Publication 260-136 Definitions of Terms and
Fluorescence Spectrometry
Modes Used at NIST for Value-Assignment of Reference
D7260 Practice for Optimization, Calibration, and Valida-
Materials for Chemical Measurements
tion of Inductively Coupled Plasma-Atomic Emission
2.3 ISO Standard:
Spectrometry (ICP-AES) for ElementalAnalysis of Petro-
ISO Guide 30 Terms and definitions used in connection with
leum Products and Lubricants
reference materials
D7303 Test Method for Determination of Metals in Lubri-
3. Terminology
cating Greases by Inductively Coupled Plasma Atomic
Emission Spectrometry
3.1 Definitions:
D7318 TestMethodforExistentInorganicSulfateinEthanol
3.1.1 calibration standard, n—material with a certified
by Potentiometric Titration
value for a relevant property, issued by or traceable to a
D7319 Test Method for Determination of Existent and Po-
national organization such as NIST, and whose properties are
tential Sulfate and Inorganic Chloride in Fuel Ethanol and known with sufficient accuracy to permit its use to evaluate the
Butanol by Direct Injection Suppressed Ion Chromatog- same property of another sample. D6792
raphy
3.1.2 certified reference material, CRM, n—reference mate-
D7328 Test Method for Determination of Existent and Po-
rial one or more of whose property values are certified by a
tential Inorganic Sulfate and Total Inorganic Chloride in
technically valid procedure, accompanied by a traceable cer-
Fuel Ethanol by Ion Chromatography Using Aqueous
tificate or other documentation which is issued by a certifying
Sample Injection
body. ISO Guide 30
D7343 Practice for Optimization, Sample Handling,
3.1.3 check standard, n—in QC testing, material having an
Calibration, and Validation of X-ray Fluorescence Spec-
accepted reference value used to determine the accuracy of a
trometry Methods for Elemental Analysis of Petroleum
measurement system.
Products and Lubricants
D7455 Practice for Sample Preparation of Petroleum and
Available from National Institute of Standards and Technology (NIST), 100
Lubricant Products for Elemental Analysis
Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov.
D7622 Test Method for Total Mercury in Crude Oil Using
Available from International Organization for Standardization (ISO), 1, ch. de
Combustion and Direct Cold Vapor Atomic Absorption
la Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http://
Method with Zeeman Background Correction www.iso.ch.
D7578 − 20
3.1.3.1 Discussion—This standard is not used to calibrate subcommittee to achieve standardized practices in all parts of
the measurement instrument or system (see calibration an analytical sequence.
standard). D7171
6. Basic Considerations
3.1.4 reference material, RM, n—material with accepted
reference value(s), accompanied by an uncertainty at a stated
6.1 All apparatus and instruments used in a laboratory
level of confidence for desired properties, which may be used
require some kind of calibration or verification before an
for calibration or quality control purposes in the laboratory.
instrument is used for producing reliable data. A perfect
3.1.4.1 Discussion—Sometimes these may be prepared “in-
analysis needs a perfect calibration as a first step and perfect
house” provided the reference values are established using
quality control as perhaps the last step in the sequence of
standard primary procedures with known precision uncertain- analytical events. Often this cycle is depicted as:
ties. See below for further discussion. D6792
Calibration→ Sample Analysis→ QC Analysis→ Calibration→→
3.1.5 traceability, n—property of the result of a measure-
6.1.1 Some test methods may additionally require a step of
ment or the value of a standard whereby it can be related to
stated references, usually national or international standards, verification of calibration using a check standard.
through an unbroken chain of comparisons all having stated
6.2 The overall program of calibration of equipment should
uncertainties. D6792
bedesignedandoperatedsoastoensurethatthemeasurements
made in the testing laboratories are traceable (where the
4. Summary of Guide
concept is applicable) to national standards of measurement,
4.1 Thisguidecoversproceduresusedforcalibratinginstru-
and where available, to international standards of measurement
ments or methods for the analysis of petroleum products or
specified by such bodies.
lubricant samples for elemental analysis measurements. The
6.2.1 Where the concept of traceability to national or
means of calibration may vary from none to elaborate depen-
international standards of measurement is not applicable, the
dent on the test method and the measurement technique used.
testing laboratory should provide satisfactory evidence of
Test method requirements will take precedence over this guide
correlation or accuracy of test results (for example, by partici-
where applicable.
pating in a suitable program of interlaboratory comparison), or
byprimaryandinterference-freeclassicalchemistrytechniques
4.2 This guide may also be applicable to non-petroleum
such as gravimetry or titrimetry.
based biofuels. Work is underway to validate this.
6.3 Different test methods require different calibration inter-
5. Significance and Use
vals. Thus, a decision about appropriate calibration frequency
5.1 Crude oil, petroleum, petroleum products, additives, shallbemadeonacasebycasebasis.However,itgoeswithout
biofuels, and lubricants are routinely analyzed for their el- sayingthatthecalibrationpracticesareamustforallanalytical
emental content such as chlorine, nitrogen, hydrogen, testing and shall be thoroughly documented both regarding the
phosphorus, sulfur, and various metals using a variety of plan and the factual evidence that it is being followed.There is
analytical techniques. Some of these methods require little to a tendency among many laboratories to do the bare minimum
no method calibration; some others require only simple one calibrations similar to their approach towards quality control
step calibration; while others require elaborate calibration requirements. This is not the way to achieve superior perfor-
routinebeforetheproductisanalyzedforitselementalcontent. mance. Moreover, if an instrument is found to be out-of-
calibration, and the situation cannot be immediately addressed,
5.2 Fairly often it can be shown that the round robin results
then the instrument shall be taken out of operation and tagged
by a co-operator are all biased with respect to those from other
as such until the situation is corrected. Under no circumstances
laboratories. Presumably, the failure to follow good laboratory
can data from that instrument be reported to the customers.
practices and instructions in the test methods can be a causal
factorofsucherrors.Afurtherconsequenceisanunnecessarily 6.4 The performance of apparatus and equipment used in
large reproducibility estimate or the data being dropped from the laboratory but not calibrated in that laboratory (that is,
the study as an outlier. pre-calibrated, vendor supplied) should be verified by using a
5.2.1 Anothercauseofsuchdiscrepanciescouldbedifferent documented, technically valid procedure at periodic intervals.
or inadequate calibration practice used in the laboratory. Most
6.5 Calibration Standards—Calibration standards appropri-
test methods spell out the calibration requirements but often do
ate for the method and characterized with the accuracy
not quote the frequency required letting the laboratories use
demanded by the analysis to be performed, shall be utilized
good laboratory practices for this task. Thus, uniform practice
during analysis. Quantitative calibration standards should be
for instrument calibration would be beneficial in standardizing
prepared from constituents of known purity. Use should be
the test procedures and obtaining consistent results across the
made of primary calibration standards or certified reference
laboratories.
materials specified or allowed in the test method. A wide
5.3 Committee D02 has already issued standard practices variety of such standards are available from commercial
for uniform sample preparation (D7455), standard operating sources, NIST, etc. Many laboratories have capabilities of
procedures for ICP-AES (D7260) and XRF (D7343) as well as preparing reliable in-house standards. Calibration standards
standard quality assurance protocol (D6792). This guide identical to the samples being analyzed would be ideal, but
should be considered as a continuing effort on behalf of this failing that, at least some type of standards shall be used to
D7578 − 20
TABLE 1 Precautions to be taken for Storage and Use of
validate the analytical sequence. In physical measurements this
Reference Materials
is usually achievable, but it is often difficult or sometimes
a. Store only in the original containers in the dark and do not subject
almost impossible in chemical measurements. Even the effects
it to variations in temperature and humidity.
of small deviations from matrix match and analyte concentra-
tionlevelmayneedtobeconsideredandevaluatedonthebasis
b. Do not heat the material in the original container for any reason,
unless so dictated by the nature of the material.
oftheoreticalorexperimentalevidence,orboth.Sometimesthe
use of standard additions technique to calibrate the measure-
c. Shake the material well before removing any material from the
ment system is a possibility. But because an artificially added original container, unless the method specifically prohibits shaking
the sample.
analyte may not necessarily respond in the same manner as a
naturally occurring analyte, this approach may not be always
d. Never place any equipment such as glass rods, metal spatulas,
valid, particularly in molecular speciation work. etc. in the original container.
NOTE 1—See Practice D4307 for recommendations in preparing liquid e. When preparing calibration standards, remove the necessary
blends for use as analytical standards. amount into a secondary container.
6.5.1 If a laboratory wants to prepare in-house calibration
f. Any material removed from the original container should never be
poured back into it.
standards,theappropriatevaluesforreferencematerialsshould
be produced following the certification protocol used by NIST
g. When two-thirds of the material has been used up, prepare
or other standards issuing bodies, and should be traceable to
additional material using standardized protocols and methods.
national or international standard reference materials, if re-
h. The long term stability of some of the calibration standard
quired or appropriate.
materials may be unknown. If any changes in appearance or other
6.5.1.1 NIST uses seven models for value assignment of characteristics are observed suggesting material instability, discard
the material and obtain a new batch of the material.
reference materials for chemical measurements: NIST certified
values are derived from certification at NIST using a single
primary method with confirmation by other method(s) or using
two independent critically-evaluated methods, or using one
methodatNISTanddifferentmethodsbyoutsidecollaborating
certification measurements were done on reference materials,
laboratories;NISTreferencevaluesarederivedfromlastofthe
which were later found to be inhomogeneous with respect to
two models mentioned, as well as values based on measure-
properties of interest. Hence, several randomly selected repre-
ments by two or more laboratories using different methods in
sentative aliquots should be analyzed first to ensure homoge-
collaboration with NIST, or based on a method specific
neity.
protocol, or NIST measurements using a single method or
6.5.3.4 Similarly, if a reference material is found to be
measurement by an outside collaborating laboratory using a
unstable over the period of its use, it would be of little benefit
single method, or based on selected data from interlaboratory
to standardization community. However, it is not very practical
studies. The last four means are used also for assigning NIST
to check the stability over an inordinately extended period of
information values. See NIST Special Publication 260-136 for
time before issuing the reference material for general use.
further details on this subject.
Hence, testing the stability of the material continues as part of
6.5.2 In addition to the oil-soluble organometallic com-
ongoing quality control of reference materials.
pounds used for the calibration of instruments such as AAS,
6.5.3.5 Whether stock or working standards, they need to be
ICP-AES, or XRF, single-element or multi-element calibration
standards may also be prepared from materials similar to the stored in clean containers and out of direct sunlight and
preferably in amber glass bottles to safeguard against physical
samples being analyzed, provided the calibration standards to
degradation and in contamination-free environment. One way
be used have previously been characterized by independent,
primary (for example, gravimetric or volumetric) analytical of checking for degradation is to measure the response of an
aliquot of the standard by the same instrument under identical
techniques to establish the elemental concentration at mass
percent levels. instrumentalconditionsoveraperiodoftimeandmonitoritfor
changes, if any. A list of suggested precautions to be taken in
6.5.3 Reference Materials (RM)—These can be classified as
storage of reference materials is given in Table 1.
primary or secondary.
6.5.3.1 The primary RMs are well-characterized, stable, 6.5.3.6 Shaking the bottle containing the standard is recom-
homogenous materials produced in quantity, and with one or mendedbeforeanaliquotistakenoutofthebottletoensurethe
more physical or chemical property experimentally uniformityoftheblends.Ifstirringisnecessary,aPTFE-coated
determined, within the stated measurement uncertainties. (polytetrafluoroethylene) magnetic stirrer is advisable. If the
These are certified by a recognized standardization laboratory test method specifically prohibits shaking then this instruction
using the most accurate and reliable measurement techniques. may not apply.
6.5.3.2 The secondary RMs are working standards or QC
6.5.4 Materials available from ASTM Proficiency Testing
standards and may have undergone less rigorous evaluation for Programs may be used provided the data does show normal
day-to-day use in the laboratory.
Gaussian distribution of results and normal frequency distri-
6.5.3.3 The two most important considerations when pre- bution. The consensus value is most likely the value closest to
paring reference materials are its homogeneity and stability. the true value of this material; however, the uncertainty
Considerable time and money would be wasted if analytical attached to this mean value is dependent on the precision and
D7578 − 20
the total number of the participating laboratories. The ex- calibration at less frequent periods (for example XRF). An
panded uncertainty of the consensus value is inversely propor- important aspect of calibration is the decision on calibration
tional to the square root of the number of laboratories (L) used intervals, that is, the maximum period between successive
to establish the consensus value. Regardless of the variance of recalibrations. Two basic and opposing considerations are
the results, for a large enough number of laboratories (L), the involved: the risk of being out of tolerance at any time of use,
uncertaintyoftheconsensusvaluewill,forsomevalueofL,be and the cost in time and effort. The former should be the major
suitable for calibration purposes. It has been observed that in concern because of the dilemma of what to do with the data
some cases the variance on the mean value of such proficiency obtained during the interval between the last known in and the
testing program is large (that is, larger than reproducibility of firstknownoutofcalibration.However,anoverlyconservative
the test method used), making such materials not very useful approach could be prohibitively expensive.Arealistic schedule
for calibration work. They are, however, suited for use as should reduce the risk of the former without undue cost and
quality control materials. disruption to work schedules. The factors that need to be
6.5.5 Analysis of CRMs—Since the CRMs will be poten- considered in a realistic schedule include:
tially used for calibration and quality control of a large number 6.7.1 Accuracy requirement for the measured data.
of instruments and measurements, the values assigned to them 6.7.2 Level of risk involved.
need to be “accurate” values, that is, they should be within the 6.7.3 Experience of the laboratory in use of the equipment
overall uncertainty of “true” values. Hence, the methods used or methodology.
in certifying the values shall have a valid and well-described 6.7.4 Experience of the measurement community.
theoretical foundation, shall have negligible systematic errors
6.7.5 Manufacturer’s recommendations.
and a high level of precision, and shall give “true” values with 6.7.6 External requirements for acceptability of data.
high reliability. These primary methods require skilled and
6.7.7 Cost of calibration and quality control.
experienced personnel, are time consuming and comparatively
6.8 An initial choice of calibration intervals may be made
expensive to perform, and perhaps uneconomical for routine
on the basis of previous knowledge or intuition. Based on the
field use. Three types of such methods may be used for
experience gained during its use, the intervals could be
certifying the CRMs.
expandedifthemethodologyisalwayswithintoleranceateach
6.5.5.1 Measurement by a method of known and demon-
recalibration, or it should be decreased if significant out-of-
strated accuracy performed by two or more analysts indepen-
tolerance is observed. Control charts may be used to monitor
dently. Frequently an accurately characterized backup method
the change of measured value of a stable test item correlated
is used to provide assurance of correctness of data.
with the need to recalibrate. Many laboratories use a posted
6.5.5.2 Measurement by two or more independent and
schedule of calibration which is followed by the analysts. This
reliable methods whose estimated inaccuracies are small,
is fine, so long as intelligent judgment is used in adhering to
relative to required accuracy for certification. The basic prin-
this schedule. If the quality control sample or routine sample
ciples of two techniques shall be entirely different, for
data produced by an instrument appears to be of doubtful
example, copper determination by electrogravimetry and tit-
quality, the first thing to check is the quality control and
rimetryisacceptable,butnotbyAASandICP-AES,sinceboth
calibration of the instrument, irrespective of what the calibra-
latter methods are based on atomic spectroscopy. The likeli-
tion schedule is.
hood of two independent methods being biased by the same
6.8.1 There are some tests (for example, ICP-AES) where
amount in the same direction is small.When the results by two
calibration is an integral part of the analysis and ASTM test
methods agree, there is a good possibility that the results are
methods explicitly state the needed frequency. In all such
accurate; three methods would almost guarantee it.
cases, this requirement shall be met.
6.5.5.3 Measurement via a worldwide network of
6.9 Calibration versus Verification—Although often the two
laboratories, using both methods of proven accuracy and using
wordsverificationandcalibrationaresynonymouslyused,they
existing certified reference materials as controls. It has to be
indeed have different connotations. Verification pertains to
recognized, however, that the mean value of results from a
checking that the instrument or a system is in a condition fit to
large number of laboratories may not necessarily represent an
use, while calibration involves standardization as in a measur-
accurate value when the repeatability and reproducibility are
ing instrument by determining the deviation from a reference
large (that is, greater than those quoted in the test method
standard so as to ascertain the proper correction factors. For
used).
example,intheD5800Noackevaporationlosstestmethod,the
6.6 Sometimes because of necessity, some values for refer-
instrument is verified with a CEC check standard that it gives
ence materials are quoted based on only one technique that
the correct value. InTest Method D892 (foam test method), the
does not qualify it as a referee method for that analysis. Such
air diffusers are verified for their maximum pore diameter and
values are usually labeled as “for information only.” These can
permeability against specifications before proceeding with the
be upgrad
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D7578 − 18 D7578 − 20
Standard Guide for
Calibration Requirements for Elemental Analysis of
Petroleum Products and Lubricants
This standard is issued under the fixed designation D7578; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This guide covers different ways by which the test methods used for elemental analysis of petroleum product and lubricant
samples are calibrated before the sample analysis.
1.2 Uniform practice for test method calibration is beneficial in standardizing the procedures, and obtaining consistent results
across different laboratories.
1.3 This guide includes only the basic steps for generally encountered instrument types. Anything out of the ordinary may
require special procedures. See individual test methods for instructions to handle such situations.
1.4 This guide is not a substitute for a thorough understanding of the actual test method to be used, caveats it contains, and
additional instrument preparation that may be required.
1.5 The user should not expand the scope of the test methods to materials or concentrations outside the scope of the test methods
being used.
1.6 This guide should also be applicable to sample preparation of non-petroleum based bio-fuels for elemental analysis. Work
is underway on these aspects in Subcommittee D02.03. As more information becomes available, it will be added to this standard.
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.9 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D129 Test Method for Sulfur in Petroleum Products (General High Pressure Decomposition Device Method)
D445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
D482 Test Method for Ash from Petroleum Products
D808 Test Method for Chlorine in New and Used Petroleum Products (High Pressure Decomposition Device Method)
D874 Test Method for Sulfated Ash from Lubricating Oils and Additives
D892 Test Method for Foaming Characteristics of Lubricating Oils
D1018 Test Method for Hydrogen In Petroleum Fractions
D1091 Test Methods for Phosphorus in Lubricating Oils and Additives
D1266 Test Method for Sulfur in Petroleum Products (Lamp Method)
D1318 Test Method for Sodium in Residual Fuel Oil (Flame Photometric Method)
1 3
D1548 Test Method for Vanadium in Heavy Fuel Oil (Withdrawn 1997)
This guide is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.03 on Elemental Analysis.
Current edition approved June 1, 2018May 1, 2020. Published June 2018June 2020. Originally approved in 2010. Last previous edition approved in 20152018 as
D7578 – 15.D7578 – 18. DOI: 10.1520/D7578-18.10.1520/D7578-20.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7578 − 20
D1552 Test Method for Sulfur in Petroleum Products by High Temperature Combustion and Infrared (IR) Detection or Thermal
Conductivity Detection (TCD)
D1839 Test Method for Amyl Nitrate in Diesel Fuels (Withdrawn 2019)
D2622 Test Method for Sulfur in Petroleum Products by Wavelength Dispersive X-ray Fluorescence Spectrometry
D2784 Standard Test Method for Sulfur in Liquefied Petroleum Gases (Oxy-Hydrogen Burner or Lamp) (Withdrawn 2016)
D3120 Test Method for Trace Quantities of Sulfur in Light Liquid Petroleum Hydrocarbons by Oxidative Microcoulometry
D3228 Test Method for Total Nitrogen in Lubricating Oils and Fuel Oils by Modified Kjeldahl Method
D3230 Test Method for Salts in Crude Oil (Electrometric Method)
D3231 Test Method for Phosphorus in Gasoline
D3237 Test Method for Lead in Gasoline by Atomic Absorption Spectroscopy
D3246 Test Method for Sulfur in Petroleum Gas by Oxidative Microcoulometry
D3340 Test Method for Lithium and Sodium in Lubricating Greases by Flame Photometer (Withdrawn 2013)
D3341 Test Method for Lead in Gasoline—Iodine Monochloride Method
D3348 Test Method for Rapid Field Test for Trace Lead in Unleaded Gasoline (Colorimetric Method)
D3605 Test Method for Trace Metals in Gas Turbine Fuels by Atomic Absorption and Flame Emission Spectroscopy
D3831 Test Method for Manganese in Gasoline By Atomic Absorption Spectroscopy
D4045 Test Method for Sulfur in Petroleum Products by Hydrogenolysis and Rateometric Colorimetry
D4046 Test Method for Alkyl Nitrate in Diesel Fuels by Spectrophotometry (Withdrawn 2019)
D4047 Test Method for Phosphorus in Lubricating Oils and Additives by Quinoline Phosphomolybdate Method
D4294 Test Method for Sulfur in Petroleum and Petroleum Products by Energy Dispersive X-ray Fluorescence Spectrometry
D4307 Practice for Preparation of Liquid Blends for Use as Analytical Standards
D4628 Test Method for Analysis of Barium, Calcium, Magnesium, and Zinc in Unused Lubricating Oils by Atomic Absorption
Spectrometry
D4629 Test Method for Trace Nitrogen in Liquid Hydrocarbons by Syringe/Inlet Oxidative Combustion and Chemiluminescence
Detection
D4927 Test Methods for Elemental Analysis of Lubricant and Additive Components—Barium, Calcium, Phosphorus, Sulfur,
and Zinc by Wavelength-Dispersive X-Ray Fluorescence Spectroscopy
D4929 Test Method for Determination of Organic Chloride Content in Crude Oil
D4951 Test Method for Determination of Additive Elements in Lubricating Oils by Inductively Coupled Plasma Atomic
Emission Spectrometry
D5056 Test Method for Trace Metals in Petroleum Coke by Atomic Absorption
D5059 Test Methods for Lead and Manganese in Gasoline by X-Ray Spectroscopy
D5184 Test Methods for Determination of Aluminum and Silicon in Fuel Oils by Ashing, Fusion, Inductively Coupled Plasma
Atomic Emission Spectrometry, and Atomic Absorption Spectrometry
D5185 Test Method for Multielement Determination of Used and Unused Lubricating Oils and Base Oils by Inductively
Coupled Plasma Atomic Emission Spectrometry (ICP-AES)
D5291 Test Methods for Instrumental Determination of Carbon, Hydrogen, and Nitrogen in Petroleum Products and Lubricants
D5384 Test Methods for Chlorine in Used Petroleum Products (Field Test Kit Method)
D5453 Test Method for Determination of Total Sulfur in Light Hydrocarbons, Spark Ignition Engine Fuel, Diesel Engine Fuel,
and Engine Oil by Ultraviolet Fluorescence
D5600 Test Method for Trace Metals in Petroleum Coke by Inductively Coupled Plasma Atomic Emission Spectrometry
(ICP-AES)
D5622 Test Methods for Determination of Total Oxygen in Gasoline and Methanol Fuels by Reductive Pyrolysis
D5708 Test Methods for Determination of Nickel, Vanadium, and Iron in Crude Oils and Residual Fuels by Inductively Coupled
Plasma (ICP) Atomic Emission Spectrometry
D5762 Test Method for Nitrogen in Liquid Hydrocarbons, Petroleum and Petroleum Products by Boat-Inlet Chemiluminescence
D5800 Test Method for Evaporation Loss of Lubricating Oils by the Noack Method
D5863 Test Methods for Determination of Nickel, Vanadium, Iron, and Sodium in Crude Oils and Residual Fuels by Flame
Atomic Absorption Spectrometry
D6334 Test Method for Sulfur in Gasoline by Wavelength Dispersive X-Ray Fluorescence
D6443 Test Method for Determination of Calcium, Chlorine, Copper, Magnesium, Phosphorus, Sulfur, and Zinc in Unused
Lubricating Oils and Additives by Wavelength Dispersive X-ray Fluorescence Spectrometry (Mathematical Correction
Procedure)
D6445 Test Method for Sulfur in Gasoline by Energy-Dispersive X-ray Fluorescence Spectrometry (Withdrawn 2009)
D6470 Test Method for Salt in Crude Oils (Potentiometric Method)
D6481 Test Method for Determination of Phosphorus, Sulfur, Calcium, and Zinc in Lubrication Oils by Energy Dispersive X-ray
Fluorescence Spectroscopy
D7578 − 20
D6595 Test Method for Determination of Wear Metals and Contaminants in Used Lubricating Oils or Used Hydraulic Fluids by
Rotating Disc Electrode Atomic Emission Spectrometry
D6667 Test Method for Determination of Total Volatile Sulfur in Gaseous Hydrocarbons and Liquefied Petroleum Gases by
Ultraviolet Fluorescence
D6728 Test Method for Determination of Contaminants in Gas Turbine and Diesel Engine Fuel by Rotating Disc Electrode
Atomic Emission Spectrometry
D6732 Test Method for Determination of Copper in Jet Fuels by Graphite Furnace Atomic Absorption Spectrometry
D6792 Practice for Quality Management Systems in Petroleum Products, Liquid Fuels, and Lubricants Testing Laboratories
D6920 Test Method for Total Sulfur in Naphthas, Distillates, Reformulated Gasolines, Diesels, Biodiesels, and Motor Fuels by
Oxidative Combustion and Electrochemical Detection (Withdrawn 2018)
D7039 Test Method for Sulfur in Gasoline, Diesel Fuel, Jet Fuel, Kerosine, Biodiesel, Biodiesel Blends, and Gasoline-Ethanol
Blends by Monochromatic Wavelength Dispersive X-ray Fluorescence Spectrometry
D7040 Test Method for Determination of Low Levels of Phosphorus in ILSAC GF 4 and Similar Grade Engine Oils by
Inductively Coupled Plasma Atomic Emission Spectrometry
D7041 Test Method for Determination of Total Sulfur in Liquid Hydrocarbons and Hydrocarbon-Oxygenate Blends by Gas
Chromatography with Flame Photometric Detection
D7111 Test Method for Determination of Trace Elements in Middle Distillate Fuels by Inductively Coupled Plasma Atomic
Emission Spectrometry (ICP-AES)
D7171 Test Method for Hydrogen Content of Middle Distillate Petroleum Products by Low-Resolution Pulsed Nuclear Magnetic
Resonance Spectroscopy
D7212 Test Method for Low Sulfur in Automotive Fuels by Energy-Dispersive X-ray Fluorescence Spectrometry Using a
Low-Background Proportional Counter
D7220 Test Method for Sulfur in Automotive, Heating, and Jet Fuels by Monochromatic Energy Dispersive X-ray Fluorescence
Spectrometry
D7260 Practice for Optimization, Calibration, and Validation of Inductively Coupled Plasma-Atomic Emission Spectrometry
(ICP-AES) for Elemental Analysis of Petroleum Products and Lubricants
D7303 Test Method for Determination of Metals in Lubricating Greases by Inductively Coupled Plasma Atomic Emission
Spectrometry
D7318 Test Method for Existent Inorganic Sulfate in Ethanol by Potentiometric Titration
D7319 Test Method for Determination of Existent and Potential Sulfate and Inorganic Chloride in Fuel Ethanol and Butanol by
Direct Injection Suppressed Ion Chromatography
D7328 Test Method for Determination of Existent and Potential Inorganic Sulfate and Total Inorganic Chloride in Fuel Ethanol
by Ion Chromatography Using Aqueous Sample Injection
D7343 Practice for Optimization, Sample Handling, Calibration, and Validation of X-ray Fluorescence Spectrometry Methods
for Elemental Analysis of Petroleum Products and Lubricants
D7455 Practice for Sample Preparation of Petroleum and Lubricant Products for Elemental Analysis
D7622 Test Method for Total Mercury in Crude Oil Using Combustion and Direct Cold Vapor Atomic Absorption Method with
Zeeman Background Correction
D7623 Test Method for Total Mercury in Crude Oil Using Combustion-Gold Amalgamation and Cold Vapor Atomic Absorption
Method
D7691 Test Method for Multielement Analysis of Crude Oils Using Inductively Coupled Plasma Atomic Emission Spectrometry
(ICP-AES)
D7740 Practice for Optimization, Calibration, and Validation of Atomic Absorption Spectrometry for Metal Analysis of
Petroleum Products and Lubricants
D7751 Test Method for Determination of Additive Elements in Lubricating Oils by EDXRF Analysis
D7757 Test Method for Silicon in Gasoline and Related Products by Monochromatic Wavelength Dispersive X-ray Fluorescence
Spectrometry
D8110 Test Method for Elemental Analysis of Distillate Products by Inductively Coupled Plasma Mass Spectrometry (ICP-MS)
D8127 Test Method for Coupled Particulate and Elemental Analysis using X-ray Fluorescence (XRF) for In-Service Lubricants
D8150 Test Method for Determination of Organic Chloride Content in Crude Oil by Distillation Followed by Detection Using
Combustion Ion Chromatography
E77 Test Method for Inspection and Verification of Thermometers
E319 Practice for the Evaluation of Single-Pan Mechanical Balances
E898 Test Method of Testing Top-Loading, Direct-Reading Laboratory Scales and Balances
D7578 − 20
2.2 NIST Standard:
NIST Special Publication 260-136 Definitions of Terms and Modes Used at NIST for Value-Assignment of Reference Materials
for Chemical Measurements
2.3 ISO Standard:
ISO Guide 30 Terms and definitions used in connection with reference materials
3. Terminology
3.1 Definitions:
3.1.1 calibration standard, n—material with a certified value for a relevant property, issued by or traceable to a national
organization such as NIST, and whose properties are known with sufficient accuracy to permit its use to evaluate the same property
of another sample. D6792
3.1.2 certified reference material, CRM, n—reference material one or more of whose property values are certified by a
technically valid procedure, accompanied by a traceable certificate or other documentation which is issued by a certifying body.
ISO Guide 30
3.1.3 check standard, n—in QC testing, material having an assigned (known) value (reference value) accepted reference value
used to determine the accuracy of the measurement system or instrument. This standard is not used to calibrate the measurement
instrument or a measurement system.
Available from National Institute of Standards and Technology (NIST), 100 Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov.
Available from International Organization for Standardization (ISO), 1, ch. de la Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http://www.iso.ch.
3.1.3.1 Discussion—
This standard is not used to calibrate the measurement instrument or system (see calibration standard). D7171
3.1.4 reference material, RM, n—material with accepted reference value(s), accompanied by an uncertainty at a stated level of
confidence for desired properties, which may be used for calibration or quality control purposes in the laboratory.
3.1.4.1 Discussion—
Sometimes these may be prepared “in-house” provided the reference values are established using standard primary procedures with
known precision uncertainties. See below for further discussion. D6792
3.1.5 traceability, n—property of the result of a measurement or the value of a standard whereby it can be related to stated
references, usually national or international standards, through an unbroken chain of comparisons all having stated uncertainties.
D6792
4. Summary of Guide
4.1 This guide covers procedures used for calibrating instruments or methods for the analysis of petroleum products or lubricant
samples for elemental analysis measurements. The means of calibration may vary from none to elaborate dependent on the test
method and the measurement technique used. Test method requirements will take precedence over this guide where applicable.
4.2 This guide may also be applicable to non-petroleum based biofuels. Work is underway to validate this.
5. Significance and Use
5.1 Crude oil, petroleum, petroleum products, additives, biofuels, and lubricants are routinely analyzed for their elemental
content such as chlorine, nitrogen, hydrogen, phosphorus, sulfur, and various metals using a variety of analytical techniques. Some
of these methods require little to no method calibration; some others require only simple one step calibration; while others require
elaborate calibration routine before the product is analyzed for its elemental content.
5.2 Fairly often it can be shown that the round robin results by a co-operator are all biased with respect to those from other
laboratories. Presumably, the failure to follow good laboratory practices and instructions in the test methods can be a causal factor
of such errors. A further consequence is an unnecessarily large reproducibility estimate or the data being dropped from the study
as an outlier.
5.2.1 Another cause of such discrepancies could be different or inadequate calibration practice used in the laboratory. Most test
methods spell out the calibration requirements but often do not quote the frequency required letting the laboratories use good
laboratory practices for this task. Thus, uniform practice for instrument calibration would be beneficial in standardizing the test
procedures and obtaining consistent results across the laboratories.
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5.3 Committee D02 has already issued standard practices for uniform sample preparation (D7455), standard operating
procedures for ICP-AES (D7260) and XRF (D7343) as well as standard quality assurance protocol (D6792). This guide should
be considered as a continuing effort on behalf of this subcommittee to achieve standardized practices in all parts of an analytical
sequence.
6. Basic Considerations
6.1 All apparatus and instruments used in a laboratory require some kind of calibration or verification before an instrument is
used for producing reliable data. A perfect analysis needs a perfect calibration as a first step and perfect quality control as perhaps
the last step in the sequence of analytical events. Often this cycle is depicted as:
Calibration → Sample Analysis → QC Analysis → Calibration → →
6.1.1 Some test methods may additionally require a step of verification of calibration using a check standard.
6.2 The overall program of calibration of equipment should be designed and operated so as to ensure that the measurements
made in the testing laboratories are traceable (where the concept is applicable) to national standards of measurement, and where
available, to international standards of measurement specified by such bodies.
6.2.1 Where the concept of traceability to national or international standards of measurement is not applicable, the testing
laboratory should provide satisfactory evidence of correlation or accuracy of test results (for example, by participating in a suitable
program of interlaboratory comparison), or by primary and interference-free classical chemistry techniques such as gravimetry or
titrimetry.
6.3 Different test methods require different calibration intervals. Thus, a decision about appropriate calibration frequency shall
be made on a case by case basis. However, it goes without saying that the calibration practices are a must for all analytical testing
and shall be thoroughly documented both regarding the plan and the factual evidence that it is being followed. There is a tendency
among many laboratories to do the bare minimum calibrations similar to their approach towards quality control requirements. This
is not the way to achieve superior performance. Moreover, if an instrument is found to be out-of-calibration, and the situation
cannot be immediately addressed, then the instrument shall be taken out of operation and tagged as such until the situation is
corrected. Under no circumstances can data from that instrument be reported to the customers.
6.4 The performance of apparatus and equipment used in the laboratory but not calibrated in that laboratory (that is,
pre-calibrated, vendor supplied) should be verified by using a documented, technically valid procedure at periodic intervals.
6.5 Calibration Standards—Calibration standards appropriate for the method and characterized with the accuracy demanded by
the analysis to be performed, shall be utilized during analysis. Quantitative calibration standards should be prepared from
constituents of known purity. Use should be made of primary calibration standards or certified reference materials specified or
allowed in the test method. A wide variety of such standards are available from commercial sources, NIST, etc. Many laboratories
have capabilities of preparing reliable in-house standards. Calibration standards identical to the samples being analyzed would be
ideal, but failing that, at least some type of standards shall be used to validate the analytical sequence. In physical measurements
this is usually achievable, but it is often difficult or sometimes almost impossible in chemical measurements. Even the effects of
small deviations from matrix match and analyte concentration level may need to be considered and evaluated on the basis of
theoretical or experimental evidence, or both. Sometimes the use of standard additions technique to calibrate the measurement
system is a possibility. But because an artificially added analyte may not necessarily respond in the same manner as a naturally
occurring analyte, this approach may not be always valid, particularly in molecular speciation work.
NOTE 1—See Practice D4307 for recommendations in preparing liquid blends for use as analytical standards.
6.5.1 If a laboratory wants to prepare in-house calibration standards, the appropriate values for reference materials should be
produced following the certification protocol used by NIST or other standards issuing bodies, and should be traceable to national
or international standard reference materials, if required or appropriate.
6.5.1.1 NIST uses seven models for value assignment of reference materials for chemical measurements: NIST certified values
are derived from certification at NIST using a single primary method with confirmation by other method(s) or using two
independent critically-evaluated methods, or using one method at NIST and different methods by outside collaborating
laboratories; NIST reference values are derived from last of the two models mentioned, as well as values based on measurements
by two or more laboratories using different methods in collaboration with NIST, or based on a method specific protocol, or NIST
measurements using a single method or measurement by an outside collaborating laboratory using a single method, or based on
selected data from interlaboratory studies. The last four means are used also for assigning NIST information values. See NIST
Special Publication 260-136 for further details on this subject.
6.5.2 In addition to the oil-soluble organometallic compounds used for the calibration of instruments such as AAS, ICP-AES,
or XRF, single-element or multi-element calibration standards may also be prepared from materials similar to the samples being
analyzed, provided the calibration standards to be used have previously been characterized by independent, primary (for example,
gravimetric or volumetric) analytical techniques to establish the elemental concentration at mass percent levels.
6.5.3 Reference Materials (RM)—These can be classified as primary or secondary.
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TABLE 1 Precautions to be taken for Storage and Use of
Reference Materials
a. Store only in the original containers in the dark and do not subject
it to variations in temperature and humidity.
b. Do not heat the material in the original container for any reason,
unless so dictated by the nature of the material.
c. Shake the material well before removing any material from the
original container, unless the method specifically prohibits shaking
the sample.
d. Never place any equipment such as glass rods, metal spatulas,
etc. in the original container.
e. When preparing calibration standards, remove the necessary
amount into a secondary container.
f. Any material removed from the original container should never be
poured back into it.
g. When two-thirds of the material has been used up, prepare
additional material using standardized protocols and methods.
h. The long term stability of some of the calibration standard
materials may be unknown. If any changes in appearance or other
characteristics are observed suggesting material instability, discard
the material and obtain a new batch of the material.
6.5.3.1 The primary RMs are well-characterized, stable, homogenous materials produced in quantity, and with one or more
physical or chemical property experimentally determined, within the stated measurement uncertainties. These are certified by a
recognized standardization laboratory using the most accurate and reliable measurement techniques.
6.5.3.2 The secondary RMs are working standards or QC standards and may have undergone less rigorous evaluation for
day-to-day use in the laboratory.
6.5.3.3 The two most important considerations when preparing reference materials are its homogeneity and stability.
Considerable time and money would be wasted if analytical certification measurements were done on reference materials, which
were later found to be inhomogeneous with respect to properties of interest. Hence, several randomly selected representative
aliquots should be analyzed first to ensure homogeneity.
6.5.3.4 Similarly, if a reference material is found to be unstable over the period of its use, it would be of little benefit to
standardization community. However, it is not very practical to check the stability over an inordinately extended period of time
before issuing the reference material for general use. Hence, testing the stability of the material continues as part of ongoing quality
control of reference materials.
6.5.3.5 Whether stock or working standards, they need to be stored in clean containers and out of direct sunlight and preferably
in amber glass bottles to safeguard against physical degradation and in contamination-free environment. One way of checking for
degradation is to measure the response of an aliquot of the standard by the same instrument under identical instrumental conditions
over a period of time and monitor it for changes, if any. A list of suggested precautions to be taken in storage of reference materials
is given in Table 1.
6.5.3.6 Shaking the bottle containing the standard is recommended before an aliquot is taken out of the bottle to ensure the
uniformity of the blends. If stirring is necessary, a PTFE-coated (polytetrafluoroethylene) magnetic stirrer is advisable. If the test
method specifically prohibits shaking then this instruction may not apply.
6.5.4 Materials available from ASTM Proficiency Testing Programs may be used provided the data does show normal Gaussian
distribution of results and normal frequency distribution. The consensus value is most likely the value closest to the true value of
this material; however, the uncertainty attached to this mean value is dependent on the precision and the total number of the
participating laboratories. The expanded uncertainty of the consensus value is inversely proportional to the square root of the
number of laboratories (L) used to establish the consensus value. Regardless of the variance of the results, for a large enough
number of laboratories (L), the uncertainty of the consensus value will, for some value of L, be suitable for calibration purposes.
It has been observed that in some cases the variance on the mean value of such proficiency testing program is large (that is, larger
than reproducibility of the test method used), making such materials not very useful for calibration work. They are, however, suited
for use as quality control materials.
6.5.5 Analysis of CRMs—Since the CRMs will be potentially used for calibration and quality control of a large number of
instruments and measurements, the values assigned to them need to be “accurate” values, that is, they should be within the overall
uncertainty of “true” values. Hence, the methods used in certifying the values shall have a valid and well-described theoretical
foundation, shall have negligible systematic errors and a high level of precision, and shall give “true” values with high reliability.
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These primary methods require skilled and experienced personnel, are time consuming and comparatively expensive to perform,
and perhaps uneconomical for routine field use. Three types of such methods may be used for certifying the CRMs.
6.5.5.1 Measurement by a method of known and demonstrated accuracy performed by two or more analysts independently.
Frequently an accurately characterized backup method is used to provide assurance of correctness of data.
6.5.5.2 Measurement by two or more independent and reliable methods whose estimated inaccuracies are small, relative to
required accuracy for certification. The basic principles of two techniques shall be entirely different, for example, copper
determination by electrogravimetry and titrimetry is acceptable, but not by AAS and ICP-AES, since both latter methods are based
on atomic spectroscopy. The likelihood of two independent methods being biased by the same amount in the same direction is
small. When the results by two methods agree, there is a good possibility that the results are accurate; three methods would almost
guarantee it.
6.5.5.3 Measurement via a worldwide network of laboratories, using both methods of proven accuracy and using existing
certified reference materials as controls. It has to be recognized, however, that the mean value of results from a large number of
laboratories may not necessarily represent an accurate value when the repeatability and reproducibility are large (that is, greater
than those quoted in the test method used).
6.6 Sometimes because of necessity, some values for reference materials are quoted based on only one technique that does not
qualify it as a referee method for that analysis. Such values are usually labeled as “for information only.” These can be upgraded
later to certified values when subsequently additional techniques or laboratories produce reliable confirmatory data.
6.7 Calibration Frequency—The calibration schedules will vary with the instrument type, some needing calibration before each
set of analysis (for example, AAS), others requiring calibration at less frequent periods (for example XRF). An important aspect
of calibration is the decision on calibration intervals, that is, the maximum period between successive recalibrations. Two basic
and opposing considerations are involved: the risk of being out of tolerance at any time of use, and the cost in time and effort. The
former should be the major concern because of the dilemma of what to do with the data obtained during the interval between the
last known in and the first known out of calibration. However, an overly conservative approach could be prohibitively expensive.
A realistic schedule should reduce the risk of the former without undue cost and disruption to work schedules. The factors that need
to be considered in a realistic schedule include:
6.7.1 Accuracy requirement for the measured data.
6.7.2 Level of risk involved.
6.7.3 Experience of the laboratory in use of the equipment or methodology.
6.7.4 Experience of the measurement community.
6.7.5 Manufacturer’s recommendations.
6.7.6 External requirements for acceptability of data.
6.7.7 Cost of calibration and quality control.
6.8 An initial choice of calibration intervals may be made on the basis of previous knowledge or intuition. Based on the
experience gained during its use, the intervals could be expanded if the methodology is always within tolerance at each
recalibration, or it should be decreased if significant out-of-tolerance is observed. Control charts may be used to monitor the change
of measured value of a stable test item correlated with the need to recalibrate. Many laboratories use a posted schedule of
calibration which is followed by the analysts. This is fine, so long as intelligent judgment is used in adhering to this schedule. If
the quality control sample or routine sample data produced by an instrument appears to be of doubtful quality, the first thing to
check is the quality control and calibration of the instrument, irrespective of what the calibration schedule is.
6.8.1 There are some tests (for example, ICP-AES) where calibration is an integral part of the analysis and ASTM test methods
explicitly state the needed frequency. In all such cases, this requirement shall be met.
6.9 Calibration versus Verification—Although often the two words verification and calibration are synonymously used, they
indeed have different connotations. Verification pertains to checking that the instrument or a system is in a condition fit to use,
while calibration involves standardization as in a measuring instrument by determining the deviation from a reference standard so
as to ascertain the proper correction factors. For example, in the D5800 Noack evaporation loss test method, the instrument is
verified with a CEC check standard that it gives the correct value. In Test Method D892 (foam test method), the air diffusers are
verified for their maximum pore diameter and permeability against specifications before proceeding with the test. In the ash test
(Test Method D482) and sash test (Test Method D874), no specific verification or calibration is done other than appropriate
thermometers for monitoring the temperature in the oven or furnace, and balance calibration. On the other hand in D4951 and
D5185 ICP-AES methods for metals, the instrument is calibrated over several concentration ranges to check that the linearity is
acceptable and other additional checks are also required.
6.9.1 Many ASTM test methods either do not specify the calibration steps or do not give the frequency of calibration. In such
cases, the incidence and the frequency is determined from prior laboratory experience, or industry practice, or both.
6.9.2 ASTM Standard Practice for Quality System in Petroleum Products and Lubricants Testing Laboratories D6792-07 states
that “Procedures shall be established to ensure that measuring and testing equipment is calibrated, maintained properly, and is in
statistical control. Items to consider when creating these procedures include:
6.9.2.1 Records of Calibration and Maintenance.
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TABLE 2 Classification of Analytical Instrumentation Used in Laboratories
Class I Class II Class III
Glassware Colorimeter AAS
Centrifuge Pressure Gauges ICP-AES
Cold Baths Hach Turbidimeter XRF
Hot Baths Titrators Thermometers (E77)
Freezers Glassware, if critical in the final results Balances (E319, E898)
Mixers ICP-MS
Stirrers GF-AAS
Shakers
Ovens
Hot Plates
Furnaces
Refrigerators
Sonic Baths
Non-Critical Thermometers
Syringe Pumps
6.9.2.2 Calibration and Maintenance Schedule.
6.9.2.3 Traceability to National or International Standards.
6.9.2.4 Requirements of the Test Method or Procedure.
6.9.2.5 Customer Requirements.
6.9.2.6 Corrective Actions.
6.10 Calibration Documentation—All calibration records should be documented either in the instrument computer software or
in manually prepared laboratory notebooks. This should include information such as date of last and next calibrations, the person
who performed the calibration, method or procedure used for calibration, the material used for calibration, the values obtained
during calibration, and the nature and traceability (if applicable) of the calibration standards. Records may be maintained
electronically.
6.10.1 For instruments that require calibration, calibration and maintenance records may be combined. See Table 2.
6.11 Types of Calibrations—The laboratory apparatus and analytical instruments used in elemental analysis can be (arguably)
divided into three categories as Class I, II, and III based on the extent of calibration needed in each case from minimal or no
calibration to extensive.
6.11.1 Class I—Apparatus include miscellaneous, unsophisticated equipment which may need no calibration or minimal
verification such as motor speed or temperature maintained. Perhaps stirrers or some types of thermometers will fall in this
category. Generally, these apparatus do not produce actual analytical data.
6.11.2 Class II—Apparatus includes equipment that should be maintained, and/or possibly calibrated on a routine basis and may
have minimal verification requirements. This might include balances, temperature controllers, gas flow meters, etc, unless the data
from these instruments is the final result of the analysis. The data from Class II instruments usually is not sent to the customers.
6.11.3 Class III—Instruments include sophisticated instrumentation/equipment that should require scheduled full verification,
or calibration, or both, as given in the standard ASTM protocols before the instrument is used for the sample analysis. These may
be done either by the analysts or outside contractors or Original Equipment Manufacturers (OEM). For all of these instruments
there are ASTM standard test methods available which should be followed in operation. The data produced from these instruments
could be provided to the customers. Some of the specifics of calibration routines for Classes I, II, and III follow:
6.12 The three most commonly used accessories in most analytical testing are temperature measuring devices, time measuring
devices, and balances.
6.12.1 Temperature Measuring Devices—These include liquid-in-glass thermometers and electronic digital thermometers and
thermocouple probes. With the increasing concern about mercury toxicity, thermometers are being replaced in the laboratories as
well as in ASTM test methods with electronic devices. These calibrated thermometers should have tags affixed to them indicating
the date of current and next calibration, correction factor, if any, and the name of the person calibrating them.
6.12.1.1 The critical TMDs are purchased from vendors with a certificate verifying that they are calibrated using ASTM
standard methods and are traceable to NIST standards. One certified set of thermometers should be used exclusively for verification
of other TMDs. Annually, the certified set of thermometers is verified using the NIST traceable standards. Over and above the
annual recalibration of TMDs, some ASTM test methods specifically require additional calibration of thermometers as a part of
the analytical procedure. Individual ASTM test methods should be consulted for details of required recalibrations. However, many
ASTM test methods do not specify the frequency of calibration.
6.12.1.2 The thermometers which are not used in analytical testing are considered non-critical and generally are not calibrated.
ASTM 120C and 121C certified liquid-in-glass thermometers used in kinematic viscosity (Test Method D445) baths are typically
controlled at working temperatures of 40 and 100°C and are verified as described in Test Method D445. This service is conducted
by an outside contractor. An ice point calibration can be done as an interim step between full calibrations. This procedure is
described in Test Method D445, Annex A2.
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TABLE 3 Suggested Calibration Frequency for Generic Laboratory Equipment
A
Instrument Calibration Frequency Possible Calibrator
Pipettes Annual In-house
Balances Annual Vendor
Volumetric Ware Only Class A materials Used
Thermometers Annual In-house or Vendor
Stop-Watches Annual In-house
Flowmeters Annual In-house or Vendor
AAS At the Time of Analysis In-house
ICP-AES At the Time of Analysis In-house
XRF Annual In-house or Manufacturer
A
Other sources for calibration services are acceptable.
6.12.1.3 In addition to general use of thermometers, the following specific test methods require monitoring using calibrated
TMDs: Test Method D482 (ash), Test Method D874 (sulfated ash), D1548 (vanadium in fuel oil), and D1552 (sulfur by high
temperature combustion).
6.12.2 Timers—Both stopwatches and electronic time measuring devices, if necessary, can be calibrated using the time signals
as broadcast by NIST and received by calling the NIST phone number in Boulder, Co. The procedure is given in Test Method
D445, Annex A3. The verification data should be recorded. Any timer not meeting the verification standard should be discarded.
No other maintenance is expected on these timers.
6.12.3 Balances—The procedure for calibration of laboratory electronic mass balances is described in E319 and E898. Balances
are usually calibrated once a year using NIST traceable standard weights. A record of such calibrations should be maintained.
6.12.4 A suggested calibration frequency for generic equipment used in elemental analysis is given in Table 3. In-house
calibrations should follow reliable procedures and protocols recommended by NIST or other recognized standards writing bodies.
7. Calibration in Empirical Test Methods
7.1 In this guide, empirical methods are defined as the methods for which no special calibration of instrumentation is necessary
or if needed is minimal. Examples of such analysis include Test Methods D129 (Sulfur by Bomb Method), D482 (Ash), D808
(Chlorine by Bomb Method), D874 (Sulfated Ash), D1018 (Hydrogen), D1091 (Phosphorus), D1266 (Sulfur by Lamp Method),
D2784, A (Sulfur), D3228 (Kjeldahl Nitrogen), D4047 (Phosphorus), and D5384 (Chlorine). In most of these cases either
gravimetric or titrimetric finish are required. Thus, only calibrations involved will be for analytical balance, temperature probe for
ashing steps, and standardization of titrants, where required.
8. Calibration in Photometric Test Methods
8.1 A number of test methods use flame emission or colorimetric measurements for quantitation of analytes, usually after
reacting the matrix with a chromogenic reagent. Such instruments need to be calibrated using appropriate standards developed by
reacting the pure metal analyte with the chromogenic reagent. The calibration curve of analyte concentration versus the
photo-signal (absorbance or transmittance) should follow Beer-Lambert Law. The sample analysis should be carried out only in
the linear range of the plot. If necessary, solutions with higher concentrations of metals should be diluted to bring them into the
linear range of calibration.
8.2 Generally, between three and eight standards are used for developing the calibration curve. The absorbance or transmittance
of standard solutions is corrected by subtracting the signal from the blank solution. If a chemical procedure is used to develop the
color, the same reagents and steps need also to be included in developing the blank color.
8.3 The test methods using such photometric methods appear in Table 4.
9. Calibration in Electrometric Test Methods
9.1 A number of elemental analysis test methods are based on final measurements using electrometric techniques such as use
of microcoulometry, thermal conductivity, chemiluminescence, UV-fluorescence, etc. Most of these test methods are used for the
determination of non-metals such as halogens, oxygen, sulfur, carbon-hydrogen-nitrogen, as well as anions such as sulfate and
chloride.
9.2 Three to six calibration standards are usually used to construct a response curve for the analysis. Specific requirements are
given in each ASTM Standard Test Methods listed below. Mostly these calibrants are pure compounds. Some examples of such
compounds are given here, although other appropriate compounds may be used for calibration if they are shown to produce
equivalent results as the following:
Nitrogen: Carbazol, Pyridine, Acridine
Sulfur: Di-Butyl Sulfide, Dibenzothiophene,
Thionaphthene, Dimethyl Sulfide
Chlorine: Chlorobenzene, Sodium Chloride
Oxygen: Anhydrous Methanol, NIST
...
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