ENV ISO 13530:1998
(Main)Water quality - Guide to analytical quality control for water analysis (ISO/TR 13530:1997)
Water quality - Guide to analytical quality control for water analysis (ISO/TR 13530:1997)
No scope available.
Wasserbeschaffenheit - Richtlinie zur analytischen Qualitätssicherung in der Wasseranalytik (ISO/TR 13530:1997)
Diese Europäische Vornorm ist eine Richtlinie mit dem Ziel, detaillierte und umfassende Anleitung über ein koordiniertes Programm zur Qualitätssicherung im Laboratorium und zwischen den Laboratorien zu geben, um Ergebnisse von angemessener und vorgegebener Genauigkeit in der Analyse von Wasser und in damit zusammenhängenden Materialien sicherzustellen. Obwohl die Probenahme ein wichtiger Aspekt ist, wird hierauf nur kurz eingegangen.
Qualité de l'eau - Guide de contrôle qualité analytique pour l'analyse de l'eau (ISO/TR 13530:1997)
Kakovost vode – Vodilo za kontrolo kakovosti analiz vode (ISO/TR 13530:1997)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-januar-2000
Kakovost vode – Vodilo za kontrolo kakovosti analiz vode (ISO/TR 13530:1997)
Water quality - Guide to analytical quality control for water analysis (ISO/TR 13530:1997)
Wasserbeschaffenheit - Richtlinie zur analytischen Qualitätssicherung in der
Wasseranalytik (ISO/TR 13530:1997)
Qualité de l'eau - Guide de contrôle qualité analytique pour l'analyse de l'eau (ISO/TR
13530:1997)
Ta slovenski standard je istoveten z: ENV ISO 13530:1998
ICS:
13.060.01 Kakovost vode na splošno Water quality in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
ISOITR
TECHNICAL
REPORT
First edition
1997-09-01
Guide to analytical quality
Water quality -
control for water analysis
Guide de contr6le qua/it& analytique pour I’analyse de
Qua/it6 de I’eau -
I’ea u
IN ADDITION TO THEIR EVALUATION AS
FOR INDUSTRIAL,
BEING ACCEPTABLE
TECHNOLOGICAL, COMMERCIAL AND USER
=--
PURPOSES, DRAFT INTERNATIONAL STAND-
ARDS MAY ON OCCASION HAVE TO BE
CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
Reference number
WHICH REFERENCE MAY BE MADE IN
ISOnR 13530:1997(E)
NATIONAL REGULATIONS.
ISO/TR 13530: 1997(E)
Contents Page
..................................................................................................
1 Scope 1
2 Normative references . 3
3 The nature and sources of analytical errors . 3
4 The quality system in water analysis . 6
5 Performance characteristics of analytical systems . 15
6 Specifying analytical requirements for water analysis . 17
7 Choosing analytical systems . 19
Initial tests to establish performance of analytical system . 24
9 Intralaboratory quality control . 33
..................................................................
10 Quality control in sampling 42
11 Interlaboratory quality control . 44
Quality control for lengthy analytical procedures .
12 46
Annexes
Evaluation of interference effects on analytical methods . 48
A
B Recovery of all forms of the determinand . 56
.........................................................
C Cali bration and blank correction 58
D .
Sample stability 63
E Bibliography . 70
0 IS0 1997
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 l CH-1211 Geneve 20 l Switzerland
Internet central @ iso.ch
x.400 c=ch; a=400net; p=iso; o=isocs; s=central
Printed in Switzerland
ii
ISOnR 13530:1997(E)
@ IS0
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work of
preparing International Standards is normally carried out through IS0
technical committees. Each member body interested in a subject for which
a technical committee has been established has the right to be represented
on that committee. International organizations, governmental and non-
governmental, in liaison with ISO, also take part in the work. IS0
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
The main task of technical committees is to prepare International
Standards, but in exceptional circumstances a technical committee may
propose the publication of a Technical Report of one of the following types:
- type 1, when the required support cannot be obtained for the
publication of an International Standard, despite repeated efforts;
- type 2, when the subject is still under technical development or where
for any other reason there is the future but not immediate possibility of
an agreement on an International Standard;
- type 3, when a technical committee has collected data of a different
kind from that which is normally published as an International Standard
(“state of the art”, for example).
Technical Reports of types 1 and 2 are subject to review within three years
of publication, to decide whether they can be transformed into International
Standards. Technical Reports of type 3 do not necessarily have to be
reviewed until the data they provide are considered to be no longer valid or
useful.
ISO/TR 13530, which is a Technical Report of type 2, was prepared by
Technical Committee ISOnC 147, Water quality, Subcommittee SC 7,
Precision and accuracy.
This document is being issued in the Technical Report (type 2) series of
publications (according to subclause G.6.2.2 of part 1 of the ISO/IEC
Directives, 1995) as a “prospective standard for provisional application” in
the field of water quality because there is an urgent need for guidance on
how standards in this field should be used to meet an identified need.
This document is not to be regarded as an “International Standard”. It is
proposed for provisional application so that information and experience of
its use in practice may be gathered. Comments on the content of this
document should be sent to the IS0 Central Secretariat.
A review of this Technical Report (type 2) will be carried out not later than
three years after its publication with the options of: extension for another
three years; conversion into an International Standard; or withdrawal.
Annexes A to E of this Technical Report are for information only.
. . .
III
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ISO/TR 13530:1997(E)
TECHNICAL REPORT @ IS0
Guide to analytical quality control for water
Water quality -
analysis
1 Scope
This Technical Report (type 2) is a guide with the objective of providing detailed and comprehensive
guidance on a coordinated programme of within-laboratory and between-laboratory quality control for
ensuring the achievement of results of adequate and specified accuracy in the analysis of waters and
associated materials.
This Technical Report and its annexes are applicable to the chemical and physicochemical analysis of
natural waters (including sea water), waste water, raw water intended for the production of potable
water, and potable water. It is not intended for application to the analysis of sludges and sediments
(although many of its general principles are applicable to such analysis) and it does not address the
biological or microbiological examination of water. Whilst sampling is an important aspect, this is only
briefly considered. I
Analytical quality control as described in this Technical Report is intended for application to water
analysis carried out within a quality assurance programme. This Technical Report does not address the
detailed requirements of quality assurance for water analysis.
The recommendations of this Technical Report are in agreement with the recommendations of
established quality assurance documentation (for example IS0 Guide 25 and EN 45001). A discussion of
quality systems in water analysis is provided in clause 4 to set in context the recommendations on
quality control.
This Technical Report is applicable to the use of all analytical methods within its field of application,
although its detailed recommendations may require interpretation and adaptation to deal with certain
types of determinand (for example non-specific determinands such as suspended solids or biochemical
oxygen demand). In the event of any disparity between the recommendations of this Technical Report
and the requirements of a standard method of analysis, the requirements of the method should prevail.
The basis of the Technical Report is to ensure the achievement of results of adequate accuracy by
adherence to the sequential stages of analytical quality control shown in figure 1.
ISOITR 13530:1997(E)
Purpose
Activity
To plan and coordinate subsequent activity.
Establish working
group
Define analytical To ensure clear specification of analytical require-
ments.
objectives
I
. .
To select methods/systems capable of the required 2 ”
Choose analytical
1 methods/systems 1) accuracy.
4. To ensure that the chosen methods are followed
Ensure unambiguous
description of methods properly.
I I
5. Estimate To ensure that each laboratory achi.eves adequate
within-laboratory precision and to check certain sources of bias.
precision and spiking
recovery
Ensure accuracy of To etiminate this source of bias in each t’aboratolry
standard solutions. and to prepare fuE& more detailed bias checks.
Preliminary check on
interla boratory bias
Set up quality control
To maintain, a continuing check on analytical perfor-
* charts mance in each laboratory.
Undertake tests of To ensure that each laboratory achieves adequately
interlaboratory checks
small errors.
To ensure long-term control of the accuracy and-
accuracy using control
comparability of analytical results.
’ charts and regular
interlaboratory tests
Figure 1: Sequence of activity for analytical quality control
1) The analytical method is the set of written instructions followed by the analyst. The analytical system includes all
aspects of producing results, i.e. method, equipment, analyst, laboratory environment, etc.
CSOflR13530:1997( E)
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions
of this Technical Report. At the time of publication, the edition indicated was valid. All standards are
subject to revision, and parties to agreements based on this Technical Report are encouraged to
investigate the possibility of applying the most recent editions of the standards indicated below.
Members of IEC and IS0 maintain registers of currently valid International Standards.
IS0 5667-l : 1980, Water quality - Sampling - Part 7: Guidance on the design of sampling programmes
IS0 5667-2:1991, Water quality - Sampling - Part 2: Guidance onsampling techniques
IS0 5667-3:1994, Water qualify - Sampling - Part 3: Guidance on the preservation and handling of
samples
IS0 8466-l: 1990, Water quality - Calibration and evaluation of analytical methods and estimation of
performance characteristics - Part 7: Statistical evaluation of the linear calibration function
IS0 8466-2:1993, Water quality - Calibration and evaluation of analytical methods and estimation of
performance characteristics - Part 2: Calibration strategy for non-linear second order ,calibration
IS0 Guide 25: 1990, General requirements for the competence of calibration and testing laboratories
. EN 45001:1989, General criteria for the operation of testing laboratories
3 The nature and sources of analytical errors
3.1 General
The following clauses provide a succinct discussion of the nature and origin of errors in analytical
results for waters and effluents. Further information on many of the topics covered is given elsewhere
in this Technical Report, and the subject is also discussed extensively in.[18].
3.2 Nature of errors
The results of chemical analysis of waters and effluents (like those of all measurement processes) are
subject to error, i.e. the measured concentrations differ from the true concentrations.
3.2.1 Total error
The total error, E, of an analytical result, R, is defined as the difference between that result and the true
value, T; i.e.
E= R-T
As the total error decreases, the accuracy of the result is said to increase.
In general, the total error represents the sum of random error and systematic error.
,ISO/TR 13530: 1997(E)
3.2.2 Random error
Repeated analysis of identical portions of the same, homogeneous sample does not, in general, lead to
a series of identical resultsz). Rather, the results are scattered about some central value. The scatter is
attributed to random error, so called because the sign and magnitude of the error of any particular
result vary at random and cannot be predicted exactly. Precision is said to improve as the scatter
becomes smaller - i.e. as random error decreases - and imprecision is therefore a synonym for random
error.
Because random errors are always present in analytical results, statistical techniques are necessary if
correct inferences regarding true values are to be made from the results.
Terms such as “repeatability” and “reproducibilty” have specialized meanings in the context of
interlaboratory collaborative trials. In this Technical Report, random error is quantified in terms of the
standard deviation, cx Since exact measurement of the standard deviation generally requires an infinite
number of repeated results, only estimates, s, of owill usually be obtainable. The number of degrees of
freedom (DF) of the estimate provides an indication of its worth; as the number of degrees of freedom
increases, the random error of the estimate itself, s, decreases.
3.2.3 Systematic error
Systematic error (or bias) is present when there is a persistent tendency for results to be greater, or
smaller, than the true value. The mean of n analytical results for identical portions of a stable, homoge-
neous sample approaches a definite, limiting value, p, as n is increased indefinitely. When p differs
from the true value, T, results are said to be subject to systematic error or bias, 8, where:
/3=p-T
Because an in
...
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