ASTM D3605-22

Standard Test Method for Trace Metals in Gas Turbine Fuels by Atomic Absorption and Flame Emission Spectroscopy

SIGNIFICANCE AND USE
5.1 Knowledge of the presence of trace metals in gas turbine fuels enables the user to predict performance and, when necessary, to take appropriate action to prevent corrosion.
SCOPE
1.1 This test method covers the determination of sodium, lead, calcium, and vanadium in Specification D2880 Grade Nos. 0-GT through 4-GT fuels at 0.5 mg/kg level for each of the elements. This test method is intended for the determination of oil-soluble metals and not waterborne contaminants in oil-water mixtures.  
1.1.1 Test Method D6728 is suggested as an alternative test method for the determination of these elements in Specification D2880.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 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.  
1.4 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-Sep-2022
• ICS: 75.160.20 - Liquid fuels
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.03 - Elemental Analysis

Relations

• Refers: ASTM D4175-23a - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 15-Dec-2023
• Refers: ASTM D4175-23e1 - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 01-Jul-2023
• Refers: ASTM D2880-18a - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 01-Oct-2018
• Refers: ASTM D2880-18 - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 01-May-2018
• Refers: ASTM D2880-15 - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 01-Jun-2015
• Refers: ASTM D2880-14a - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 01-Dec-2014
• Refers: ASTM D2880-14 - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 01-Aug-2014
• Refers: ASTM D2880-13b - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 15-Nov-2013
• Refers: ASTM D2880-13a - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 01-Aug-2013
• Refers: ASTM D2880-13 - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 01-May-2013
• Refers: ASTM D6728-11 - Standard Test Method for Determination of Contaminants in Gas Turbine and Diesel Engine Fuel by Rotating Disc Electrode Atomic Emission Spectrometry
• Effective Date: 01-Oct-2011
• Refers: ASTM D4057-06(2011) - Standard Practice for Manual Sampling of Petroleum and Petroleum Products
• Effective Date: 01-Jun-2011
• Refers: ASTM D2880-03(2010) - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 01-Oct-2010
• Refers: ASTM D6728-01(2006) - Standard Test Method for Determination of Contaminants in Gas Turbine and Diesel Engine Fuel by Rotating Disc Electrode Atomic Emission Spectrometry
• Effective Date: 01-May-2006
• Refers: ASTM D2880-03 - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 10-May-2003

Overview

ASTM D3605-22 is the international standard test method for measuring trace metals in gas turbine fuels using atomic absorption and flame emission spectroscopy. Developed by ASTM International, this standard is essential for analyzing the concentrations of sodium, lead, calcium, and vanadium in gas turbine fuel oils as specified in ASTM D2880, covering Grade Nos. 0-GT through 4-GT. The method is specifically designed for identifying oil-soluble metals at levels as low as 0.5 mg/kg for each element, which is critical for ensuring fuel quality and operational reliability in gas turbine engines.

By accurately detecting trace metal contamination, users can assess the risk of corrosion, optimize maintenance schedules, and support compliance with industry and regulatory requirements. This standard is widely recognized for enhancing safety, efficiency, and the longevity of gas turbine systems.

Key Topics

Trace Metals Detection in Gas Turbine Fuels

• Elements Analyzed: Sodium, lead, calcium, and vanadium
• Applicable Fuels: ASTM D2880 Grades 0-GT through 4-GT
• Limit of Detection: Capable of detecting metals at 0.5 mg/kg levels

Test Methods

• Atomic Absorption Spectroscopy (AAS): Provides high sensitivity for metal analysis in oil-based samples
• Flame Emission Spectroscopy: An alternative for select sample matrices, particularly for sodium, calcium, and vanadium
• Sample Preparation: Utilization of the method of standard additions to counteract variations in sample properties
• Quality Control: Incorporates mixed standard solutions, blank corrections, and accuracy checks with independent standards

Instrumentation Requirements:

• Atomic absorption spectrophotometer equipped with required burner heads and detection systems
• Hollow cathode lamps for each target element
• Supporting laboratory glassware and high-purity reagents

Applications

Gas Turbine Operation and Maintenance

• Fuel Quality Monitoring: Precise determination of trace metals helps prevent corrosion of hot section turbine parts, extending equipment service life
• Performance Optimization: Early detection of contaminants allows for corrective actions before significant damage occurs
• Regulatory Compliance: Supports adherence to specifications for trace metal content in turbine fuels, minimizing the risk of environmental or safety violations

Industrial and Laboratory Uses

• Refineries and Fuel Suppliers: Used for product certification and quality control before shipment or use
• Power Generation: Assists in fuel acceptance testing and routine system monitoring
• Environmental Testing: Offers a validated approach for laboratories tasked with fuel analysis and research

Related Standards

• ASTM D2880: Specification for Gas Turbine Fuel Oils - defines the grades and quality requirements for fuels compatible with D3605-22.
• ASTM D6728: Alternate test method for contaminants in gas turbine and diesel engine fuels using rotating disc electrode atomic emission spectrometry.
• ASTM D4057: Manual sampling procedures for petroleum and petroleum products.
• ASTM D4175: Terminology relating to petroleum products and liquid fuels.
• ASTM D4177: Practice for automatic sampling of petroleum products.

For comprehensive and reliable gas turbine fuel quality testing, adherence to ASTM D3605-22 and the above standards is strongly recommended. This ensures consistent, accurate detection of trace metals, supporting both operational excellence and regulatory requirements in the energy, aviation, and industrial sectors.

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: D3605 − 22
Standard Test Method for
Trace Metals in Gas Turbine Fuels by Atomic Absorption
and Flame Emission Spectroscopy
This standard is issued under the fixed designation D3605; 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* D4177 Practice for Automatic Sampling of Petroleum and
Petroleum Products
1.1 This test method covers the determination of sodium,
D6728 Test Method for Determination of Contaminants in
lead, calcium, and vanadium in Specification D2880 Grade
Gas Turbine and Diesel Engine Fuel by Rotating Disc
Nos. 0-GT through 4-GT fuels at 0.5 mg⁄kg level for each of
Electrode Atomic Emission Spectrometry
the elements. This test method is intended for the determina-
tion of oil-soluble metals and not waterborne contaminants in
3. Terminology
oil-water mixtures.
3.1 Definitions:
1.1.1 Test Method D6728 is suggested as an alternative test
3.1.1 For definitions of terms used in this test method, refer
methodforthedeterminationoftheseelementsinSpecification
to Terminology D4175.
D2880.
1.2 The values stated in SI units are to be regarded as
4. Summary of Test Method
standard. No other units of measurement are included in this
4.1 The samples are prepared to conform with the require-
standard.
ments of the method of standard additions, which is selected to
1.3 This standard does not purport to address all of the
obviate problems encountered with the direct analysis of
safety concerns, if any, associated with its use. It is the
typical gas turbine fuels that exhibit significant variations in
responsibility of the user of this standard to establish appro-
physical properties. Different, but known, amounts of analyte
priate safety, health, and environmental practices and deter-
are added to two portions of sample. These, together with the
mine the applicability of regulatory limitations prior to use.
unaltered sample, are burned in the flame of an atomic
1.4 This international standard was developed in accor-
absorption instrument that measures light absorption by the
dance with internationally recognized principles on standard-
atomized metals. The analysis of the sample portions with
ization established in the Decision on Principles for the
addedanalyteprovidesthecalibrationinformationnecessaryto
Development of International Standards, Guides and Recom-
calculate the analyte content of the unaltered sample.
mendations issued by the World Trade Organization Technical
4.2 Lead is determined by atomic absorption in a premixed
Barriers to Trade (TBT) Committee.
air-acetylene flame, and sodium is determined by atomic
2. Referenced Documents
absorption or atomic emission in a premixed air-acetylene
flame. Calcium and vanadium are determined by atomic
2.1 ASTM Standards:
absorption or atomic emission in a premixed nitrous oxide-
D2880 Specification for Gas Turbine Fuel Oils
acetylene flame.
D4057 Practice for Manual Sampling of Petroleum and
Petroleum Products 4.3 Most experience with this test method has been in the
D4175 Terminology Relating to Petroleum Products, Liquid
atomic absorption mode, although flame emission has been
Fuels, and Lubricants used successfully. Details in the subsequent sections are
written for the atomic absorption mode. If the flame emission
mode is used, minor details in the subsequent sections must be
This test method is under the jurisdiction of ASTM Committee D02 on
altered to conform to standard practice for flame emission
Petroleum Products, Liquid Fuels, and Lubricantsand is the direct responsibility of
spectroscopy. The precision statement applies only to the
Subcommittee D02.03 on Elemental Analysis.
Current edition approved Oct. 1, 2022. Published October 2022. Originally atomic absorption mode.
approved in 1977. Last previous edition approved in 2017 as D3605 – 17. DOI:
NOTE 1—Some GT fuel users may wish to determine potassium in
10.1520/D3605-22.
addition to other metals included in this method. Potassium can be
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
determined in a manner similar to that for sodium using a potassium
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on hollow cathode lamp, (unless flame emission mode is used) a wavelength
the ASTM website. of 766.4 mm, and an appropriate organo-potassium standard. Precision
*A Summary of Changes section appears at the end of this standard
Copyright ©ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959. United States
D3605 − 22
data for potassium have not been determined.
such specifications are available. Other grades may be used,
provided it is ascertained that the reagent is of sufficiently high
5. Significance and Use
purity to permit its use without lessening the accuracy of the
determination.
5.1 Knowledgeofthepresenceoftracemetalsingasturbine
7.2 1,2,3,4-tetrahydronaphthalene, practical grade,
fuels enables the user to predict performance and, when
analyte-sterile.
necessary, to take appropriate action to prevent corrosion.
NOTE3—Analyte-sterile1,2,3,4-tetrahydronaphthalenecanbeprepared
6. Apparatus by extracting a portion of tetralin with an equal amount of hydrochloric
acid in a covered screw-cap vial. Heat the vial on a steam bath for1hand
6.1 Atomic Absorption Spectrometer, capable of measuring
shake the vial for 1 h. If the acid extracted 1,2,3,4-tetrahydronaphthalene
and unextracted 1,2,3,4-tetrahydronaphthalene give indistinguishable ab-
radiation over the wavelength range from 280 nm to 600 nm.
sorption signals for each of the analytes under optimal experimental
Theinstrumentmustbecapableofmeasuringlow-levelsignals
conditions, the unextracted 1,2,3,4-tetrahydronaphthalene can be used
(approximately 1 % absorption or 0.004 absorbance unit per
throughout this method.
milligram per litre vanadium). The instrument should also be
7.3 Organometallic Standards—Oil-soluble salts of sodium,
equipped as follows.
lead, calcium, and vanadium of known concentration.
6.1.1 Burner, with variable nebulizer and auxiliary oxidant
7.4 Mixed Standard—Prepare a mixed standard containing
supply to reduce non-atomic absorption from unburned hydro-
250 mg⁄L each of sodium, lead, calcium, and vanadium by
carbons which cause interferences.
dissolvingtheappropriateamountsoforganometallicstandards
6.1.1.1 Burner Head, capable of supporting a nitrous oxide-
in 1,2,3,4-tetrahydronaphthalene and making the required di-
acetylene flame.
lutions. Prepare fresh daily, as needed.
6.1.1.2 Burner Head, single- or multiple-slot, capable of
7.5 Quality Control Samples, preferably are portions of one
supporting an air-acetylene flame.
or more liquid petroleum materials that are stable and repre-
6.1.2 Electronic Detection System, capable of reading to the
sentative of the samples of interest. These QC samples can be
nearest 0.1 % absorption or 0.0004 absorbance.
used to check the validity of the testing process as described in
Section 9.
6.1.2.1 The text describes the measurement of absorption
signals that is, either percent absorption or absorbance. For
8. Sampling
instruments reading in percent absorption, absorption signals
of 0.1 % absorption must be measurable. For instruments
8.1 Samples shall be taken in accordance with the instruc-
reading in absorbance, signals of 0.0004 absorbance must be
tions in Practice D4057 or D4177.
measurable.
9. Procedure
6.1.3 Hollow Cathode Lamp Power Supply, regulated to
minimize drift.
9.1 Fill two clean 25 mL volumetric flasks to the line with
6.1.4 Monochromator, capable of resolving the 318.34 nm – sample. With the microlitre syringe add 50 µL of mixed
318.40 nm vanadium doublet from the 318.54 nm vanadium standard to one flask and 100 µLto the other. Touch the needle
of the syringe to the inner wall of the flask to ensure
line.
quantitative transfer of the standard. Invert and mix the
6.1.5 Hollow Cathode Lamps, one each for calcium,
contents. (The two flasks are now spiked with 0.5 mg⁄L and
sodium, lead, and vanadium.
1.0 mg⁄L of sodium, lead, calcium, and vanadium).
NOTE 2—Electrodeless-discharge lamps can be an acceptable
Alternatively, weigh 25.0 g of sample into each of two clean
alternative, but the precision of this method was determined with hollow
disposableglassvialsandaddthestandardinthesamemanner.
cathode lamps.
6.1.6 When the instrument has flame-emission capability,
the emission technique can be used for the analyses of sodium,
ACS Reagent Chemicals, Specifications and Procedures for Reagents and
Standard-Grade Reference Materials, American Chemical Society, Washington,
calcium, and vanadium.
DC. For suggestions on the testing of reagents not listed by theAmerican Chemical
Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
6.2 Volumetric Flasks, 25 mL.
U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma-
copeial Convention, Inc. (USPC), Rockville, MD.
6.3 Glass Vials, 40 mL, screw-cap type, polyethylene-lined
Tetralin (1,2,3,4-tetrahydronaphthalene), manufactured by E. I. duPont de
caps.
Nemours and Co., has been found satisfactory. If you are aware of alternative
suppliers, please provide this information to ASTM International Headquarters.
6.4 Syringe, 100 µL, Hamilton type or equivalent.
Your comments wil
...

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: D3605 − 17 D3605 − 22
Standard Test Method for
Trace Metals in Gas Turbine Fuels by Atomic Absorption
and Flame Emission Spectroscopy
This standard is issued under the fixed designation D3605; 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 test method covers the determination of sodium, lead, calcium, and vanadium in Specification D2880 Grade Nos. 0-GT
through 4-GT fuels at 0.5 mg ⁄kg level for each of the elements. This test method is intended for the determination of oil-soluble
metals and not waterborne contaminants in oil-water mixtures.
1.1.1 Test Method D6728 is suggested as an alternative test method for the determination of these elements in Specification
D2880.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 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:
D2880 Specification for Gas Turbine Fuel Oils
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
D6728 Test Method for Determination of Contaminants in Gas Turbine and Diesel Engine Fuel by Rotating Disc Electrode
Atomic Emission Spectrometry
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this test method, refer to Terminology D4175.
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricantsand is the direct responsibility of Subcommittee
D02.03 on Elemental Analysis.
Current edition approved June 1, 2017Oct. 1, 2022. Published June 2017October 2022. Originally approved in 1977. Last previous edition approved in 20162017 as
D3605 – 16.D3605 – 17. DOI: 10.1520/D3605-17.10.1520/D3605-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*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
D3605 − 22
4. Summary of Test Method
4.1 The samples are prepared to conform with the requirements of the method of standard additions, which is selected to obviate
problems encountered with the direct analysis of typical gas turbine fuels that exhibit significant variations in physical properties.
Different, but known, amounts of analyte are added to two portions of sample. These, together with the unaltered sample, are
burned in the flame of an atomic absorption instrument that measures light absorption by the atomized metals. The analysis of the
sample portions with added analyte provides the calibration information necessary to calculate the analyte content of the unaltered
sample.
4.2 Lead is determined by atomic absorption in a premixed air-acetylene flame, and sodium is determined by atomic absorption
or atomic emission in a premixed air-acetylene flame. Calcium and vanadium are determined by atomic absorption or atomic
emission in a premixed nitrous oxide-acetylene flame.
4.3 Most experience with this test method has been in the atomic absorption mode, although flame emission has been used
successfully. Details in the subsequent sections are written for the atomic absorption mode. If the flame emission mode is used,
minor details in the subsequent sections must be altered to conform to standard practice for flame emission spectroscopy. The
precision statement applies only to the atomic absorption mode.
NOTE 1—Some GT fuel users may wish to determine potassium in addition to other metals included in this method. Potassium can be determined in a
manner similar to that for sodium using a potassium hollow cathode lamp, (unless flame emission mode is used) a wavelength of 766.4 mm, and an
appropriate organo-potassium standard. Precision data for potassium have not been determined.
5. Significance and Use
5.1 Knowledge of the presence of trace metals in gas turbine fuels enables the user to predict performance and, when necessary,
to take appropriate action to prevent corrosion.
6. Apparatus
6.1 Atomic Absorption Spectrophotometer,Spectrometer, capable of measuring radiation over the wavelength range from 280 nm
to 600 nm. The instrument must be capable of measuring low-level signals (approximately 1 % absorption or 0.004 absorbance unit
per milligram per litre vanadium). The instrument should also be equipped as follows.
6.1.1 Burner, with variable nebulizer and auxiliary oxidant supply to reduce non-atomic absorption from unburned hydrocarbons
which cause interferences.
6.1.1.1 Burner Head, capable of supporting a nitrous oxide-acetylene flame.
6.1.1.2 Burner Head, single- or multiple-slot, capable of supporting an air-acetylene flame.
6.1.2 Electronic Detection System, capable of reading to the nearest 0.1 % absorption or 0.0004 absorbance.
6.1.2.1 The text describes the measurement of absorption signals that is, either percent absorption or absorbance. For instruments
reading in percent absorption, absorption signals of 0.1 % absorption must be measurable. For instruments reading in absorbance,
signals of 0.0004 absorbance must be measurable.
6.1.3 Hollow Cathode Lamp Power Supply, regulated to minimize drift.
6.1.4 Monochromator, capable of resolving the 318.34 nm –
318.40 nm vanadium doublet from the 318.54 nm vanadium line.
6.1.5 Hollow Cathode Lamps, one each for calcium, sodium, lead, and vanadium.
NOTE 2—Electrodeless-discharge lamps can be an acceptable alternative, but the precision of this method was determined with hollow cathode lamps.
6.1.6 When the instrument has flame-emission capability, the emission technique can be used for the analyses of sodium, calcium,
and vanadium.
D3605 − 22
6.2 Volumetric Flasks, 25 mL.
6.3 Glass Vials, 40 mL, screw-cap type, polyethylene-lined caps.
6.4 Syringe, 100 μL, Hamilton type or equivalent.
7. Reagents
7.1 Purity of Reagents—Reagent grade chemicals shall be used in tests. Unless otherwise indicated, it is intended that all reagents
conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where such
specifications are available. Other grades may be used, provided it is ascertained that the reagent is of sufficiently high purity to
permit its use without lessening the accuracy of the determination.
7.2 1,2,3,4-tetrahydronaphthalene, practical grade, analyte-sterile.
NOTE 3—Analyte-sterile 1,2,3,4-tetrahydronaphthalene can be prepared by extracting a portion of tetralin with an equal amount of hydrochloric acid in
a covered screw-cap vial. Heat the vial on a steam bath for 1 h and shake the vial for 1 h. If the acid extracted 1,2,3,4-tetrahydronaphthalene and
unextracted 1,2,3,4-tetrahydronaphthalene give indistinguishable absorption signals for each of the analytes under optimal experimental conditions, the
unextracted 1,2,3,4-tetrahydronaphthalene can be used throughout this method.
7.3 Organometallic Standards—Oil-soluble salts of sodium, lead, calcium, and vanadium of known concentration.
7.4 Mixed Standard—Prepare a mixed standard containing 250 mg ⁄L each of sodium, lead, calcium, and vanadium by dissolving
the appropriate amounts of organometallic standards in 1,2,3,4-tetrahydronaphthalene and making the required dilutions. Prepare
fresh daily, as needed.
7.5 Quality Control Samples, preferably are portions of one or more liquid petroleum materials that are stable and representative
of the samples of interest. These QC samples can be used to check the validity of the testing process as described in Section 89.
8. Sampling
8.1 Samples shall be taken in accordance with the instructions in Practice D4057 or D4177.
9. Procedure
9.1 Fill two clean 25 mL volumetric flasks to the line with sample. With the microlitre syringe add 50 μL of mixed standard to
one flask and 100 μL to the other. Touch the needle of the syringe to the inner wall of the flask to ensure quantitative transfer of
the standard. Invert and mix the contents. (The two flasks are now spiked with 0.5 mg ⁄L and 1.0 mg ⁄L of sodium, lead, calcium,
and vanadium). Alternatively, weigh 25.0 g of sample into each of two clean disposable glass vials and add the standard in the same
manner. (The two vials are now spiked with 0.5 mg ⁄kg and 1.0 mg ⁄kg of sodium, lead, calcium, and vanadium.)
9.2 Prepare a third spiked sample by adding approximately 1 mL of the mixed standard to approximately 25 mL of sample. This
solution serves only to aid in establishing satisfactory operating conditions for the atomic absorption instrument.
9.3 Establish the atomic absorption instrument operating conditions, which are recommended by the manufacturer, and consider
the following special points. Select the mode, flame gases, and spectral lines from the information presented in Table 1.
Reagent Chemicals, American Chemical Society Specifications,ACS Reagent Chemicals, Specifications and Procedures for Reagents and Standard-Grade Reference
...