ASTM D5172-91(2004)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation:D5172–91(Reapproved2004)
Standard Guide for
Documenting the Standard Operating Procedures Used for
the Analysis of Water
This standard is issued under the fixed designation D5172; 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 5. Significance and Use
5.1 The exact analytical test methods and procedures used
1.1 This guide addresses the need for each laboratory
engagedintheanalysisofwaterandwastewatertodevelopand inanylaboratorymaybeuniqueandaffecttheusabilityoftheir
maintain an up-to-date written manual that clearly and com- analytical results. A general reference to a book of standard
pletely delineates the exact steps followed in performing every analytical test methods, guides, and practices published by a
test method and procedure used in the laboratory, that is, a reputable organization such as ASTM is not sufficient to
manual of their standard operating procedures (SOPs). guarantee acceptable results. As a point of clarification, a
1.2 This guide details the practices necessary to provide procedure may be part of a test method or it may be any other
clear in-house SOPs and a mechanism whereby the normal routine process the laboratory personnel must follow, for
development and evolution of an analytical test method or example, glassware cleaning, quality control, routine mainte-
procedure can be controlled and properly evaluated for incor- nance, or data reporting procedures.
poration into the SOP used in that laboratory. 5.2 A significant part of the variability of results generated
1.3 This standard does not purport to address all of the by different laboratories analyzing the same samples and citing
safety concerns, if any, associated with its use. It is the the same general reference is due to differences in the way the
responsibility of the user of this standard to establish appro- analytical test methods and procedures are actually performed
priate safety and health practices and determine the applica- in each laboratory. These differences are often caused by the
bility of regulatory limitations prior to use. Specific precau- slightchangesoradjustmentsallowedbythegeneralreference,
tionary statements are given in the note. but that can affect the final results.
5.3 The manual of SOPs is an important component of any
2. Referenced Documents
laboratory’s quality assurance program. As with all quality
2.1 ASTM Standards:
assurance activities, the importance of this manual lies in its
D1129 Terminology Relating to Water
impact on maintaining uniformity of test method performance
and the utility of data generated by the laboratory.
3. Terminology
5.4 Each laboratory should develop and maintain a loose-
3.1 Definitions—For definitions of terms used in this guide,
leaf manual containing an exact step-by-step description of
refer to Terminology D1129.
how every test method and procedure is performed in the
3.2 Definitions of Terms Specific to This Standard:
laboratory to help guarantee uniform performance among
3.2.1 procedure— any process involving sequential steps
different analysts using them.
conducted to achieve a specific objective.
5.5 With adequate documentation of a laboratory’s com-
plete and exact analytical test methods and procedures, a
4. Summary of Guide
laboratory will have improved confidence in its ability to
4.1 This guide describes suggested practices for developing
reproduce analytical conditions exactly and thereby general
and maintaining a current compilation of the complete and
reproducible results.This manual of SOPs is the cornerstone of
exact analytical test methods and procedures being used in a
a laboratory’s creditability.
particular laboratory.
6. Suggested Steps for Generating a Manual of SOPs
6.1 The manual should begin with specification of the
This guide is under the jurisdiction of ASTM Committee D19 on Water and is
the direct responsibility of Subcommittee D19.02 on General Specifications,
published references from a standard-setting organization or
Technical Resources, and Statistical Methods.
regulatory agency. An adequate written SOP should then be
Current edition approved Sept. 19, 1991. Published February 1992. DOI:
drafted in-house for each test method or procedure performed
10.1520/D5172-91R04.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or by the laboratory. A standard format should be used that is
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
appropriate to the SOP and is similar in scope to the formats
Standards volume information, refer to the standard’s Document Summary page on
included in this guide asAnnexA1 andAnnexA2.All aspects
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D5172–91 (2004)
of the test method or procedure as actually applied in the 7. Centralized Files
laboratory should be addressed in detail.
7.1 A master copy of the laboratory’s SOPs should be kept
on-file under the control of the quality assurance officer.
NOTE 1—Caution: When a laboratory is performing an analytical
procedure in a regulatory or legal environment, it is of vital importance Whenever a procedure is modified, the revised version should
that the in-house version be maintained within the technical allowances of
be documented and the changes highlighted. Copies of the
the mandated procedure. Technical departures from the mandated proce-
revised SOP should be distributed to the staff to replace the
dure may result in a legal liability. One way to demonstrate consistency
previous version, that they should destroy, and a new effective
with the mandated procedure is to copy the standard procedure as
date for the revision and a revised copy of the SOP should be
published and add footnotes to fully document the specific in-house
added to the master file along with an explanation of why the
version.
revision was necessary. Out-of-date versions of an SOPshould
6.2 The basic structure and elements of a test method are
be filed separately by the QA officer for future reference.
typically present in consensus standards published by groups
Through use of such an updating mechanism, the laboratory
such as ASTM. But, invariably, these published test methods
will be able to identify the exact procedure being followed at
and procedures must be interpreted for application in each
the time a particular result was generated.
laboratory. Published versions of other test methods and
procedures are often very general or completely unavailable.
8. Suggested Use and Maintenance
6.3 In generating a draft SOP, it is often helpful to solicit
8.1 While performing an SOP, the analyst should have a
input from analysts experienced with a test method or proce-
copy of the current documentation readily at-hand and follow
dure who are familiar with its vagaries and pitfalls, and can
it to the letter. If the SOP allows for multiple options, the
provide valuable assistance in writing a complete and exact
option employed should be noted with the final results.
document on how the procedure is done in the laboratory. It is
8.2 When an analyst encounters a situation for which no
often useful to have all of the analytical staff review the final
clear direction is provided in the SOP, possible changes should
draft.
be discussed with a qualified supervisor, and approved and
6.4 After an initial draft to identify the pertinent details of
documented before use.
an SOP, the laboratory should conduct a study to verify its
8.3 Records should be maintained of the distribution of the
applicability to the sample matrices encountered in that par-
laboratory’s SOPs and their revisions.
ticular laboratory. In addition, the laboratory should verify that
it can, at a minimum, obtain results with precision and bias
9. Procedure Audits
equivalent to those in published references (if available for
9.1 For a variety of reasons, procedures as they are actually
similar matrices). The precision and bias obtained in the study
appliedinthelaboratoryhaveatendencytodriftawayfromthe
should be recorded for future use relating to evaluation of
approved written versions. For this reason, the actual perfor
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