ASTM D6850-03(2008)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D6850 − 03(Reapproved 2008)
Standard Guide for
QC of Screening Methods in Water
This standard is issued under the fixed designation D6850; 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 in the batch. The number of samples in the batch is defined by
the task group responsible for the method.
1.1 This guide covers general considerations for the Quality
3.2.2.1 Discussion—See Practice D5847 for definition and
Control practices for use with screening methods for organic
discussion of batch and batch size.
and inorganic constituents in water. Methods are provided by
3.2.3 false negative, n—a negative response for a sample
variousstandardsettingbodies,governmentalagencies,aswell
as many domestic and international manufacturers. that contains the target analyte(s) at or above the stated action
level.
1.2 This guide provides general QC procedures that are
3.2.4 false positive, n—a positive response for a sample that
applicable to a broad range of screening methodologies. These
contains the target analyte(s) below the stated action level.
procedures help to ensure the quality of data that is generated.
Additional, method-specific or project specific requirements
3.2.5 qualitative method, n—a validated method that detects
may be necessary. This guide also includes general consider-
presence or absence of an analyte at a specified screening limit.
ations regarding proper utilization of screening methods.
3.2.6 screening limit, n—the concentration of analyte that
can be determined with a given certainty. The task group
2. Referenced Documents
responsible for the method establishes the determination of the
2.1 ASTM Standards: screening limit.
D1129 Terminology Relating to Water
3.2.7 screening method, n—amethodthatisusedtoseparate
D4840 Guide for Sample Chain-of-Custody Procedures
or categorize samples.
D5172 Guide for Documenting the Standard Operating Pro-
3.2.7.1 Discussion—An example would be a method that
cedures Used for the Analysis of Water
provides results that would be used to separate samples into
D5847 Practice for Writing Quality Control Specifications
those that contain an analyte above or below a specified action
for Standard Test Methods for Water Analysis
level.
D5905 Practice for the Preparation of Substitute Wastewater
3.2.8 semi-quantitative method Type 1, n— a method whose
results are given in specified, discreet concentration ranges.
3. Terminology
3.2.8.1 Discussion—Two types of examples of this would
3.1 Definitions—For definitions of terms used in this guide,
include semi-quantitative immunoassays or test strips. The
refer to Terminology D1129 and Practice D5847.
cutoff concentration of the ranges has been predefined.
3.2 Definitions of Terms Specific to This Standard:
3.2.9 semi-quantitative method Type 2, n— a method whose
3.2.1 action level, n—a concentration of the analyte of
results are reported as a single number along with the stated
concern at which some further action is required or suggested.
uncertainty.
3.2.9.1 Discussion—The uncertainty will be reported as
3.2.2 batch, n—a set (group) of samples analyzed such that
(standard deviation of x at a concentration of y). The values of
results of analysis of the QC samples analyzed with the batch
x and y can be established from the Initial Demonstration of
areindicativeofthequalityoftheresultsofanalysisofsamples
Performance study.
4. Significance and Use
This guide is under the jurisdiction of ASTM Committee D19 on Water and is
the direct responsibility of Subcommittee D19.05 on Inorganic Constituents in
4.1 Screening methods are often used to determine the
Water.
presence or absence of a specific analyte, groups of analytes,
Current edition approved May 1, 2008. Published May 2008. Originally
classes of compounds or other indicators of chemical com-
approved in 2003. Last previous edition approved in 2003 as D6850 – 03. DOI:
10.1520/D6850-03R08.
pounds in order to determine if further analysis or action is
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
necessary. The determination whether to proceed with further
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
action is useful in reducing the number of negative results for
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. which the screening method serves as a surrogate.
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D6850 − 03 (2008)
4.2 The use of screening methods, whether to generate 6.1.3 It is required that the analyst using the screening
qualitative or semi-quantitative results, is increasingly becom- method proves their proficiency with the test. The task group
ingausefultoolforregulatorymonitoring,processcontrol,and responsible for the method will establish proficiency require-
site characterization. The appropriate use of a screening ments.
method, or any other method for that matter, is dependent upon
6.1.4 When performing matrix evaluations it is recom-
the Data Quality Objectives (DQOs) that are defined by the
mended to use the actual matrix if possible. If not, a similar
user of the data.
matrix should be used. Example: Use substitute wastewater, as
described in Practice D5905, for a wastewater matrix.This will
4.3 Persons responsible for assessing the quality of the data
determinethesuitabilityofthemethodinthematrixofinterest.
generatedbytheuseofscreeningmethodsshouldhavedetailed
It is also suggested a laboratory control sample (LCS) be run in
Quality Control guidelines by which to assess data quality.
a representative matrix.
6.1.5 It is recommended that all screening methods be
5. Consideration for Selection of an Appropriate
compared to a reference method to provide further detail of the
Screening Method
screening methods capabilities and limitations. This is useful
5.1 The screening method chosen must be appropriate for
when establishing or verifying false positives/ negatives and
the Action Level of the project.
recoveries in actual samples.
6.1.6 Specific requirements of a QC system for screening
5.2 The chosen screening method must allow for the nec-
methods will be dependent upon the type of analysis being
essary number of samples to be run in a timely manner, not to
performed.
exceed the storage limits of the sample as defined by the
6.1.7 Semi-quantitative Type 2 methods require either pre-
method.
paring a user-generated calibration curve pri
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