ASTM D6328-18

Standard Guide for Quality Assurance Protocols for Chemical Analysis of Atmospheric Wet Deposition

ABSTRACT
This guide describes quality assurance protocols for the determination of the anions and cations in atmospheric wet deposition which include the minimum recommended requirements for the preparation of calibration standards and suggested procedures for validating laboratory measurement results. Specimens to be used in all tests shall consist of reagent grade chemicals, water, and standard solutions. Common techniques for chemical analysis include automated colorimetry; ion chromatography, flame atomic absorption spectrophotometry, electrometry, and inductively coupled plasma spectrometry. Analytical precision and bias determinations shall be done for evaluation of the reference materials. Samples for reanalysis may be selected from the evaluation of control charts and the calculation of ion and conductivity percent differences.
SCOPE
1.1 This guide describes quality assurance (QA) protocols for the determination of the anions and cations in Atmospheric Wet Deposition (AWD) shown in Table 1.  
1.2 Included in this guide are minimum recommended requirements for the preparation of calibration standards and suggested procedures for validating laboratory measurement results.  
1.3 This guide describes minimum requirements for the frequency of analysis of quality assurance samples and recommends procedures for the evaluation of quality assurance data.  
1.4 The guide's recommendations are based upon expected anion and cation concentrations in AWD (1)2 and Appendix X1.  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.6 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.  
1.7 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-2018
• ICS: 03.120.10 - Quality management and quality assurance
• ICS: 13.040.20 - Ambient atmospheres
• ICS: 71.040.40 - Chemical analysis
• Technical Committee: D22 - Air Quality
• Drafting Committee: D22.03 - Ambient Atmospheres and Source Emissions

Relations

• Replaces: ASTM D6328-12 - Standard Guide for Quality Assurance Protocols for Chemical Analysis of Atmospheric Wet Deposition
• Effective Date: 01-May-2018
• Refers: ASTM D1356-20a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Sep-2020
• Refers: ASTM D1356-20 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 15-Mar-2020
• Refers: ASTM D1356-15a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 15-Oct-2015
• Refers: ASTM D1356-15 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Jul-2015
• Refers: ASTM D1356-14b - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Dec-2014
• Refers: ASTM D1356-14a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-May-2014
• Refers: ASTM D1356-14 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 15-Jan-2014
• Refers: ASTM D5086-01(2013) - Standard Test Method for Determination of Calcium, Magnesium, Potassium, and Sodium in Atmospheric Wet Deposition by Flame Atomic Absorption Spectrophotometry
• Effective Date: 01-Oct-2013
• Refers: ASTM D3856-11 - Standard Guide for Management Systems in Laboratories Engaged in Analysis of Water
• Effective Date: 15-Nov-2011
• Refers: ASTM D596-01(2011) - Standard Guide for Reporting Results of Analysis of Water
• Effective Date: 01-May-2011
• Refers: ASTM D1356-05(2010) - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Apr-2010
• Refers: ASTM D5085-02(2008) - Standard Test Method for Determination of Chloride, Nitrate, and Sulfate in Atmospheric Wet Deposition by Chemically Suppressed Ion Chromatography
• Effective Date: 01-Aug-2008
• Refers: ASTM D5015-02(2008) - Standard Test Method for pH of Atmospheric Wet Deposition Samples by Electrometric Determination
• Effective Date: 01-Aug-2008
• Refers: ASTM D5086-01(2008) - Standard Test Method for Determination of Calcium, Magnesium, Potassium, and Sodium in Atmospheric Wet Deposition by Flame Atomic Absorption Spectrophotometry
• Effective Date: 01-Apr-2008

Overview

ASTM D6328-18: Standard Guide for Quality Assurance Protocols for Chemical Analysis of Atmospheric Wet Deposition provides a comprehensive framework for ensuring the reliability, accuracy, and comparability of laboratory results when measuring anions and cations in atmospheric wet deposition (AWD). This guide highlights essential quality assurance (QA) protocols so environmental laboratories and monitoring programs can consistently deliver credible chemical analysis of precipitation, essential for air quality and environmental research.

Adherence to these protocols helps laboratories detect and correct measurement errors, maintain the integrity of standard solutions, and validate instrument performance. The standard covers the minimum recommended requirements for calibration, validation, frequency of QA samples, and the evaluation of QA data across common techniques such as automated colorimetry, ion chromatography, flame atomic absorption spectrophotometry, electrometry, and inductively coupled plasma spectrometry.

Key Topics

• Quality Assurance Protocols

  • Procedures for preparation, verification, and storage of calibration standards
  • Validation of laboratory measurement results through reference materials and interlaboratory comparisons

• Sample and Reagent Handling

  • Use of reagent grade chemicals and Type I water for all sample preparations
  • Recommended containers for storing standard solutions to avoid contamination

• Analytical Techniques

  • Commonly accepted methods including automated colorimetry, ion chromatography, flame atomic absorption spectrophotometry, electrometry, and inductively coupled plasma spectrometry
  • Routine performance checks using reference materials and blanks

• Data Quality Assessment

  • Use of control charts to monitor analytical precision and bias
  • Criteria for the reanalysis of samples based on statistical evaluations like ion percent difference and conductivity percent difference
  • Definition and ongoing recalculation of method detection limits (MDL) and method reporting limits (MRL)

• Participation in Intercomparisons

  • Encouragement of regular participation in laboratory intercomparison studies to ensure analytical consistency across different laboratories

Applications

The protocols detailed in ASTM D6328-18 are essential for:

• Environmental Monitoring Networks

  • Ensures consistent, high-quality chemical analysis in networks such as national and regional precipitation monitoring programs

• Regulatory Compliance

  • Supports laboratories in meeting air and water quality regulatory standards by providing documented QA/QC procedures

• Scientific Research

  • Facilitates comparable datasets for studies on atmospheric chemistry, acid deposition, and long-term climate and ecosystem impacts

• Data Validation

  • Enables scientists and regulators to identify out-of-control conditions and address contamination or analytical drift proactively

Related Standards

This guide is designed to be used with several other ASTM standards to build a robust QA program for atmospheric wet deposition analysis:

• ASTM D1193: Specification for Reagent Water
• ASTM E200: Practice for Preparation, Standardization, and Storage of Standard and Reagent Solutions for Chemical Analysis
• ASTM D5012: Guide for Preparation of Materials Used for the Collection and Preservation of Atmospheric Wet Deposition
• ASTM D5015: Test Method for pH of Atmospheric Wet Deposition Samples by Electrometric Determination
• ASTM D5085: Test Method for Determination of Chloride, Nitrate, and Sulfate in Atmospheric Wet Deposition by Chemically Suppressed Ion Chromatography
• ASTM D5086: Test Method for Determination of Calcium, Magnesium, Potassium, and Sodium in Atmospheric Wet Deposition by Flame Atomic Absorption Spectrophotometry
• ASTM D5111: Guide for Choosing Locations and Sampling Methods to Monitor Atmospheric Deposition at Non-Urban Locations
• ASTM D1356: Terminology Relating to Sampling and Analysis of Atmospheres

Conclusion

ASTM D6328-18 guides laboratories in achieving high standards in the chemical analysis of atmospheric wet deposition, supporting reliable data for environmental assessment and regulatory decisions. By incorporating these quality assurance protocols, laboratories can strengthen data quality, meet international standards, and support critical research and monitoring initiatives focused on atmospheric deposition and its environmental effects.

Keywords: atmospheric deposition, wet deposition, quality assurance, anion analysis, cation analysis, laboratory protocols, ASTM D6328-18, precipitation chemistry, environmental monitoring, QA/QC

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: D6328 − 18
Standard Guide for
Quality Assurance Protocols for Chemical Analysis of
Atmospheric Wet Deposition
This standard is issued under the fixed designation D6328; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This guide describes quality assurance (QA) protocols
D596Guide for Reporting Results of Analysis of Water
for the determination of the anions and cations inAtmospheric
D1193Specification for Reagent Water
Wet Deposition (AWD) shown in Table 1.
D1356Terminology Relating to Sampling and Analysis of
1.2 Included in this guide are minimum recommended
Atmospheres
requirements for the preparation of calibration standards and
D3856Guide for Management Systems in Laboratories
suggested procedures for validating laboratory measurement
Engaged in Analysis of Water
results.
D5012Guide for Preparation of Materials Used for the
Collection and Preservation of Atmospheric Wet Deposi-
1.3 This guide describes minimum requirements for the
tion
frequency of analysis of quality assurance samples and recom-
D5015Test Method for pH ofAtmospheric Wet Deposition
mends procedures for the evaluation of quality assurance data.
Samples by Electrometric Determination
1.4 The guide’s recommendations are based upon expected
D5085Test Method for Determination of Chloride, Nitrate,
anion and cation concentrations in AWD (1) and Appendix
andSulfateinAtmosphericWetDepositionbyChemically
X1.
Suppressed Ion Chromatography
D5086 Test Method for Determination of Calcium,
1.5 The values stated in SI units are to be regarded as
Magnesium, Potassium, and Sodium in Atmospheric Wet
standard. No other units of measurement are included in this
Deposition by FlameAtomicAbsorption Spectrophotom-
standard.
etry
1.6 This standard does not purport to address all of the
D5111Guide for Choosing Locations and Sampling Meth-
safety concerns, if any, associated with its use. It is the
ods to Monitor Atmospheric Deposition at Non-Urban
responsibility of the user of this standard to establish appro- Locations
priate safety, health, and environmental practices and deter-
E200Practice for Preparation, Standardization, and Storage
mine the applicability of regulatory limitations prior to use. of Standard and Reagent Solutions for ChemicalAnalysis
1.7 This international standard was developed in accor-
3. Terminology
dance with internationally recognized principles on standard-
3.1 Definitions—For definitions of terms used in this guide
ization established in the Decision on Principles for the
refer to Terminology D1356 or the ASTM Dictionary of
Development of International Standards, Guides and Recom-
Engineering Science and Technology.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
4. Summary of Guide
4.1 This guide describes QA procedures to be used in
conjunction with standard test methods.
This guide is under the jurisdiction of ASTM Committee D22 on Air Quality
and is the direct responsibility of Subcommittee D22.03 on Ambient Atmospheres
and Source Emissions. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved May 1, 2018. Published May 2018. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1998. Last previous edition approved in 2012 as D6328–12. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D6328-18. the ASTM website.
2 4
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof ASTM Dictionary of Engineering Science and Technology, Tenth Edition,
this guide. 2005. Stock# DEF05.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6328 − 18
TABLE 1 Common Techniques of Analysis for Atmospheric Wet
7.1.3 Comparison of the standard solution analyte concen-
Deposition Samples
trations of the same standard solution prepared by different
Automated Colorimetry Ion Chromatography
analystsfromthesamelaboratoryorcomparisonoftheanalyte
+ – – 2– + 2+
NH Cl ,NO ,SO ,NH ,Ca ,
4 3 4 4
concentration of the new standard solution with the analyte
2+ + +
Mg ,Na ,K
concentration of a prior standard solution; or
Flame Atomic Absorption Spectrophotometry Electrometric
+ + 2+ 2+
Na ,K ,Ca ,Mg pH, specific conductance
7.1.4 Comparison of the analyte concentration from the
Inductively Coupled Plasma Spectrometry
+ + 2+ 2+ standardsolutionwiththeconcentrationofacertifiedreference
Na ,K ,Ca ,Mg
material (CRM) (2).
7.2 If the confidence intervals of the two measurements (at
4.2 This guide does not include all components of a com- a 95% confidence level) intersect, the two solutions are
pleteQAprogramforAWDmeasurementsystemsbutprovides statistically the same. New standard solution(s) must be pre-
minimum protocols to assist in the development of such a pared if the results are not in statistical agreement.
program. The procedures for the preparation of materials used
for the collection and preservation of AWD are included in
8. Reference Materials
Guide D5012. The procedures for choosing locations and
8.1 Thereferencematerials(RM)shouldbeacommercially
samplingatmosphericdepositionareincludedinGuideD5111.
available CRM.
5. Reagents
8.2 Immediately following calibration (Test Methods
D5015, D5085, D5086), at least one RM is to be analyzed to
5.1 Purity of Reagents—Reagent grade chemicals shall be
ensure that the system is functioning properly and that stan-
used in all tests. Unless otherwise indicated, it is intended that
dards were correctly prepared and that no degradation or
all reagents shall conform to the specifications of the commit-
contamination of the standards has occurred.The frequency of
tee onAnalytical Reagents of theAmerican Chemical Society
RManalysisisspecifiedinthetestmethodbutmustbeatleast
(ACS),wheresuchspecificationsareavailable. Otherreagents
one per analytical run.
may be used provided it can be demonstrated that they are of
sufficiently high purity to permit their use without decreasing
8.3 Evaluation of RM Data—Compare the measured RM
the accuracy of the determination.
concentrationtothecertifiedvalueimmediatelyaftermeasure-
ment. The analyst must ensure that the concentration value
5.2 Purity of Water—Unless otherwise indicated, reference
falls within the limits previously established from the repeated
towatershallbeunderstoodtomeanreagentwaterconforming
analysis of solutions at that concentration level. The measure-
to Specification D1193, Type I.
ment of samples must be suspended whenever the RM mea-
5.3 Standard Solutions—Unless otherwise indicated, refer-
surement system is out of control.
ence to standard solutions shall be understood to mean solu-
tions conforming to Practice E200. Standard solutions are NOTE 1—If the confidence interval (at a 95% confidence level) of the
measurement intersects the confidence or tolerance interval of the RM,
preparedfromprimarystandardsorACSreagentgradesaltsor
there is agreement. If not, then a discrepancy exists that needs to be
may be purchased as secondary standards from commercial
investigated (2).
laboratory suppliers.
8.3.1 When the concentration of the RM differs from the
6. Storage of Standard Solutions
certified value by greater than the established acceptance
limits, reanalyze the RM immediately to determine if the
6.1 TFE-fluorocarbon, polyethylene, and polypropylene
current measurement is reproducible. If this second measure-
containers are recommended for the storage of standard solu-
ment also differs from the acceptance limits about the certified
tions. Glass containers are not suitable for storage of most
value, cease analyzing samples.
standardsolutionsneededtoanalyzeAWDduetothepotential
8.3.2 WheneverRMvaluesindicatethatthesystemisoutof
for sodium contamination.
control, determine the reason and perform corrective action.
7. Verification of Standard Solutions
Reanalyze all samples measured after the last RM value that
was in control.
7.1 Use two or more of the following procedures to ensure
that the standard solutions are correctly formulated.
9. Blanks
7.1.1 Confirmation of standard solution analyte concentra-
tion by an independent laboratory determination;
9.1 Preparation and Frequency of Analysis:
7.1.2 Confirmation of standard solution analyte concentra-
9.1.1 Prepare reagent blanks according to the procedures
tion by an independent analytical procedure within the labora-
recommended in the appropriate test method. Use water
tory.
conforming to Specification D1193, Type I.
9.1.2 Measure reagent blanks each day determinations are
performed or whenever new reagents are used to check for
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
contamination in sample preparation or analysis.
listed by the American Chemical Society, see Analar Standards for Laboratory
9.1.3 Use field blanks for analytes whose expected concen-
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
trations are less than 1 mg/L. Field blanks are Type I water
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
MD. samples subjected to all aspects of sample collection, field
D6328 − 18
processing, preservation, transportation, and laboratory han- 10.3 Every laboratory must determine its own MDL values
dling as an environmental sample. for each analyte.
9.1.4 Other types of blanks may be necessary to determine
10.4 Annotatedatareportedforsamplesthatcontainanalyte
the cleanliness of collection vessels, sample storage bottles,
concentrations lower than the MDLto indicate that concentra-
and membrane filters. Refer to Guide D5012 or the EPA
tions lower than the detection limit have been measured.
Quality Assurance Handbook for Air Pollution Measurement
10.5 MDL values must be recalculated at least yearly or
Systems,VolumeIIforprocedures (3)forguidanceonspecific
whenever instrumental operating conditions are modified.
procedures and criteria.
11. Precision and Bias
9.2 Evaluation of Blank Data:
NOTE 2—Blind samples are samples submitted for analysis whose
9.2.1 Reagent blank contamination can be highly variable
composition is known to the submitter but unknown to the analyst. A
depending on the source of contamination. When variable
double blind sample is one of known composition that is submitted to the
concentrations of analytes are found in reagent blanks, the analyst in such a manner that neither its composition nor its identification
are known to the analyst.
source(s) of contamination should be determined and mini-
mized.
11.1 Blindsamplesarearecommendedsubsetofthenormal
9.2.2 Subtracttheconcentrationoftheanalyteinthereagent sample flow to determine the precision and bias of the
analytical methods. Prepare control charts or a statistical
blank from the concentration of the analyte in the sample only
whentheanalyteconcentrationintheblankislow,forexample tabulation of the blind sample data as soon as analysis results
are available. The submission of blind samples must be
<1%, in relation to the samples being measured and its value
is constant. When the analyte concentration in the blank is performed by someone other than the analyst.
11.1.1 Samples used to assess intra-day repeatability (pre-
highlyvariable,reanalyzesamplessuspectedofcontamination.
cision) may include duplicate, split, blind and double blind
9.2.3 Field blank contamination is often more variable than
samples, and calibration check standards. Samples used to
reagent blanks. The field blank concentrations should be used
assess inter-day repeatability may include delayed reanalysis,
todetermineiftheAWDsampleanalyteconcentrationsarereal
split, blind and double blind samples, and calibration check
orartifacts.Fieldblankconcentrationsofanalytesarenottobe
standards. The precision characteristics of the intra-day and
routinelysubtractedfromAWDsampleanalyteconcentrations.
inter-day samples may differ. Data from the two sample sets,
therefore, should not be presented on a single control chart or
10. Detection Limit Definition
in a combined statistical summary.
10.1 To improve the comparability of AWD data, it is
11.1.2 Samples used to determine bias include CRM, blind
strongly recommended that the following definition of method
and double blind, and laboratory spike samples.
detection limit be adopted and implemented.
11.2 Perform analytical precision and bias determinations
10.1.1 Method Detection Limit (MDL)—Theminimumcon-
on a scheduled basis following the procedure listed in the test
centration of an analyte that can be reported with 99%
method. Evaluate each precision and bias determination by
confidence to have a value that is above zero. The MDL is 6
plotting the data in a control-chart format.
operationally defined as:
11.2.1 Compare the current precision and bias results with
MDL
...

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: D6328 − 12 D6328 − 18
Standard Guide for
Quality Assurance Protocols for Chemical Analysis of
Atmospheric Wet Deposition
This standard is issued under the fixed designation D6328; 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 describes quality assurance (QA) protocols for the determination of the anions and cations in Atmospheric Wet
Deposition (AWD) shown in Table 1.
1.2 Included in this guide are minimum recommended requirements for the preparation of calibration standards and suggested
procedures for validating laboratory measurement results.
1.3 This guide describes minimum requirements for the frequency of analysis of quality assurance samples and recommends
procedures for the evaluation of quality assurance data.
1.4 The guide’s recommendations are based upon expected anion and cation concentrations in AWD (1) and Appendix X1.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 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.
1.7 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:
D596 Guide for Reporting Results of Analysis of Water
D1193 Specification for Reagent Water
D1356 Terminology Relating to Sampling and Analysis of Atmospheres
D3856 Guide for Management Systems in Laboratories Engaged in Analysis of Water
D5012 Guide for Preparation of Materials Used for the Collection and Preservation of Atmospheric Wet Deposition
D5015 Test Method for pH of Atmospheric Wet Deposition Samples by Electrometric Determination
D5085 Test Method for Determination of Chloride, Nitrate, and Sulfate in Atmospheric Wet Deposition by Chemically
Suppressed Ion Chromatography
D5086 Test Method for Determination of Calcium, Magnesium, Potassium, and Sodium in Atmospheric Wet Deposition by
Flame Atomic Absorption Spectrophotometry
D5111 Guide for Choosing Locations and Sampling Methods to Monitor Atmospheric Deposition at Non-Urban Locations
E200 Practice for Preparation, Standardization, and Storage of Standard and Reagent Solutions for Chemical Analysis
This guide is under the jurisdiction of ASTM Committee D22 on Air Quality and is the direct responsibility of Subcommittee D22.03 on Ambient Atmospheres and
Source Emissions.
Current edition approved Oct. 1, 2012May 1, 2018. Published November 2012May 2018. Originally approved in 1998. Last previous edition approved in 20062012 as
D6328 – 06.D6328 – 12. DOI: 10.1520/D6328-12.10.1520/D6328-18.
The boldface numbers in parentheses refer to the list of references at the end of this guide.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6328 − 18
TABLE 1 Common Techniques of Analysis for Atmospheric Wet
Deposition Samples
Automated Colorimetry Ion Chromatography
+ – – 2– + 2+
NH Cl , NO , SO , NH , Ca ,
4 3 4 4
2+ + +
Mg , Na , K
Flame Atomic Absorption Spectrophotometry Electrometric
+ + 2+ 2+
Na , K , Ca , Mg pH, specific conductance
Inductively Coupled Plasma Spectrometry
+ + 2+ 2+
Na , K , Ca , Mg
3. Terminology
3.1 Definitions—For definitions of terms used in this guide refer to Terminology D1356 or the ASTM Dictionary of Engineering
Science and Technology.
4. Summary of Guide
4.1 This guide describes QA procedures to be used in conjunction with standard test methods.
4.2 This guide does not include all components of a complete QA program for AWD measurement systems but provides
minimum protocols to assist in the development of such a program. The procedures for the preparation of materials used for the
collection and preservation of AWD are included in Guide D5012. The procedures for choosing locations and sampling
atmospheric deposition are included in Guide D5111.
5. Reagents
5.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the committee on Analytical Reagents of the American Chemical Society (ACS),
where such specifications are available. Other reagents may be used provided it can be demonstrated that they are of sufficiently
high purity to permit their use without decreasing the accuracy of the determination.
5.2 Purity of Water—Unless otherwise indicated, reference to water shall be understood to mean reagent water conforming to
Specification D1193, Type I.
5.3 Standard Solutions—Unless otherwise indicated, reference to standard solutions shall be understood to mean solutions
conforming to Practice E200. Standard Solutionssolutions are prepared from primary standards or ACS reagent grade salts or may
be purchased as secondary standards from commercial laboratory suppliers.
6. Storage of Standard Solutions
6.1 TFE-fluorocarbon, polyethylene, and polypropylene containers are recommended for the storage of standard solutions.
Glass containers are not suitable for storage of most standard solutions needed to analyze AWD due to the potential for sodium
contamination.
7. Verification of Standard Solutions
7.1 Use two or more of the following procedures to ensure that the standard solutions are correctly formulated.
7.1.1 Confirmation of standard solution analyte concentration by an independent laboratory determination;
7.1.2 Confirmation of standard solution analyte concentration by an independent analytical procedure within the laboratory.
7.1.3 Comparison of the standard solution analyte concentrations of the same standard solution prepared by different analysts
from the same laboratory or comparison of the analyte concentration of the new standard solution with the analyte concentration
of a prior standard solution; or
7.1.4 Comparison of the analyte concentration from the standard solution with the concentration of a certified reference material
(CRM) (2).
7.2 If the confidence intervals of the two measurements (at a 95 % confidence level) intersect, the two solutions are statistically
the same. New standard solution(s) must be prepared if the results are not in statistical agreement.
8. Reference Materials
8.1 The reference materials (RM) should be a commercially available CRM.
ASTM Dictionary of Engineering Science and Technology, Tenth Edition, 2005. Stock# DEF05.
Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed by
the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National
Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
D6328 − 18
8.2 Immediately following calibration (Test Methods D5015, D5085, D5086), at least one RM is to be analyzed to ensure that
the system is functioning properly and that standards were correctly prepared and that no degradation or contamination of the
standards has occurred. The frequency of RM analysis is specified in the test method but must be at least one per analytical run.
8.3 Evaluation of RM Data—Compare the measured RM concentration to the certified value immediately after measurement.
The analyst must ensure that the concentration value falls within the limits previously established from the repeated analysis of
solutions at that concentration level. The measurement of samples must be suspended whenever the RM measurement system is
out of control.
NOTE 1—If the confidence interval (at a 95 % confidence level) of the measurement intersects the confidence or tolerance interval of the RM, there
is agreement. If not, then a discrepancy exists that needs to be investigated (2).
8.3.1 When the concentration of the RM differs from the certified value by greater than the established acceptance limits,
reanalyze the RM immediately to determine if the current measurement is reproducible. If this second measurement also differs
from the acceptance limits about the certified value, cease analyzing samples.
8.3.2 Whenever RM values indicate that the system is out of control, determine the reason and correct the condition.perform
corrective action. Reanalyze all samples measured after the last RM value that was in control.
9. Blanks
9.1 Preparation and Frequency of Analysis:
9.1.1 Prepare reagent blanks according to the procedures recommended in the appropriate test method. Use water conforming
to Specification D1193, Type I.
9.1.2 Measure reagent blanks each day determinations are performed or whenever new reagents are used to check for
contamination in sample preparation or analysis.
9.1.3 Use field blanks for analytes whose expected concentrations are less than 1 mg/L. Field blanks are Type I water samples
subjected to all aspects of sample collection, field processing, preservation, transportation, and laboratory handling as an
environmental sample.
9.1.4 Other types of blanks may be necessary to determine the cleanliness of collection vessels, sample storage bottles, and
membrane filters. Refer to Guide D5012 for or the EPA Quality Assurance Handbook for Air Pollution Measurement Systems,
Volume II for procedures (3)specific procedures. for guidance on specific procedures and criteria.
9.2 Evaluation of Blank Data:
9.2.1 Reagent blank contamination can be highly variable depending on the source of contamination. When variable
concentrations of analytes are found in reagent blanks, the source(s) of contamination should be determined and minimized.
9.2.2 Subtract the concentration of the analyte in the reagent blank from the concentration of the analyte in the sample only
when the analyte concentration in the blank is low, for example <1 %, in relation to the samples being measured and its value is
constant. When the analyte concentration in the blank is highly variable, reanalyze samples suspected of contamination.
9.2.3 Field blank contamination is often more variable than reagent blanks. The field blank concentrations should be used to
determine if the AWD sample analyte concentrations are real or artifacts. Field blank concentrations of analytes are not to be
routinely subtracted from AWD sample analyte concentrations.
10. Detection Limit Definition
10.1 To improve the comparability of AWD data, it is strongly recommended that the following definition of method detection
limit be adopted and implemented.
10.1.1 Method Detection Limit (MDL)—The minimum concentration of an analyte that can be reported with 99 % confidence
to have a value that is above zero. The MDL is operationally defined as:
MDL 5 St (1)
~n21, 12a50.99!
where:
S = the standard deviation of a minimum of seven measurements of a solution containing the analyte at a
concentration near the lowest calibration standard recommended in the test method, and
t = the student’s t value for a one-tailed test at the 99 % confidence level and n-1 degrees of freedom.
(n-1, 1-a = 0.99)
Obtain the data used to calculate the standard deviation (S) during seven separate analyses by measuring a freshly prepared
standard solution in a matrix that matches the calibration solutions; that is, a new solution is prepared and measured on each of
seven different days. Use a solution concentration not greater than five times the estimated MDL (34).
10.2 Method Reporting Limits (MRL)—The MRL is defined as 2–10 times the MDL. The MRL should remain constant for the
study period design of the project. The MDL may vary throughout the study period but should always remain less than the MRL.
10.3 Every laboratory must determine its own MDL values for each analyte.
10.4 Annotate data reported for samples that contain analyte concentrations lower than the MDL to indicate that concentrations
lower than the detection limit have been measured.
D6328 − 18
10.5 MDL values must be recalculated at least yearly or whenever instrumental operating conditions are modified.
11. Precision and Bias
NOTE 2—Blind samples are samples submitted for analysis whose composition is known to the submitter but unknown to the analyst. A double blind
sample is one of known composition that is submitted to the analyst in such a manner that neither its composition nor its identification are known to the
analyst.
11.1 Blind samples are a recommended subset of the normal sample flow to determine the precision and bias of the analytical
methods. Prepare control charts or a statistical tabulation of the blind sample data as soon as analysis results are available. The
submission of blind samples must be performed by someone other than the analyst, typically the laboratory manager, dir
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