ISO/TR 13530:1997

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
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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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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 indefinitely large number of determinations cannot be made on a single sample, the effect
of random error prevents exact determination of p, and hence also of 8. Only an estimate, X, of p will
generally be available, so that only an estimate, b, of /3 can be obtained.
As the systematic error or bias of results decreases, trueness is said to increase.
3.3 Sources of error
The distinction between random and systematic errors is important for two reasons: first, because they
have different effects on the use to be made of analytical results, and second, because they usually
have different origins.
Causes of random error
3.3.1
Random errors arise from uncontrolled variations in the conditions of the analytical system 3) during
different analyses. The nature of such variations include, for example, differences in the volume of
sample or reagent taken on different occasions, fluctuations in temperature - either in time, or across
the different sample positions in a heating bath, block or oven, fluctuations in instrumental conditions
(for example in temperatures, fluid flowrates, voltages and wavelengths) and operator-induced
variations in reading scales. Variations from batch to batch, in the extent to which the calibration
function represents the true calibration for that batch, also give rise to between-batch random errors,
whereas a consistent calibration error across many batches gives rise to systematic error - see below.
This may not be true when the discrimination of the analytical system is coarse. However, the apparent perfect
2)
concordance of repeated results in such a situation is illusory, because samples differing in concentration will also
give the same results.
The analytical system is the combination
of all factors - analyst, equipment, method, reagents, etc. involved in
producing analytical results from samples.
ISOPTR 13530:1997(E)
Whilst many of these factors causing random errors can be more closely controlled to achieve better
precision, they can never be totally eliminated, so that all results are subject to some-degree of random
error.
3.3.2 Causes of systematic error
There are five general sources of systematic error (if clear blunders by the analyst in carrying out the
written method, and bias introduced by the sample collection itself are both excluded). .
These are:
Instability of samples between sample collection and analysis
a)
This is a potentially important source of error in many cases, and evidence should
always be obtained - either from the literature or by direct test - to ensure that
unacceptable bias is not introduced by this factor. Effective sample stabilization
procedures are available for many determinands, but they should be compatible with
the analytical system being employed, and with the particular sample type being
analysed.
Inability to determine all relevant forms of the determinand
b)
Many substances exist in water in a variety of physical and/or chemical forms (or
“species”). For example, iron can exist in both dissolved and particulate forms, and
within each of those physical categories a variety of chemical species may be present -
for example free ions and complexes, including those of different oxidation states, in
the dissolved phase. An inability of the analytical system to determine some of the
forms of interest will give rise to a bias when those forms are present in samples.
Some determinands are overall properties of a sample, rather than a particular
substance - for example biochemical oxygen demand (BOD). Such determinands are
called “non-specific” and have to be carefully defined by specifying the use of a
particular analytical method. The so-called “dissolved’ fractions of, for example trace
metals, are also non-specific in the sense that the type and pore-size of filter toe be used
in their determination should be clearly specified.
Interferences
d
Few analytical methods are completely specific for the determinand. Response to
another substance (for example, response to iron by a spectrophotometric procedure
for manganese based on formaldoxime) will give rise to biased results substance is present in samples, and it is important that the effects of all such
intetferents likely to be present in samples are known before a new method is applied
routinely.
In some cases, the effect of another substance is to alter the chemical state of the
determinand such that it is not measured by the method being used - for example, the
presence of fluoride will cause aluminium complexes to form, which may not be
measured by an ion-selective electrode. Such an effect can be regarded as an
interference upon the determination of total dissolved aluminium, or as a failure to
recover all forms of dissolved aluminium. Although it more strictly falls into the latter
category, the effect - and others like it - may be most conveniently treated as an
interference when data on performance characteristics are being obtained or reported
(see clause 5 and annex A).
@ IS0
ISOmR 13!S30:1997(E)
Biased calibration
d)
Most methods require the use of a calibration function (explicit or implicit) to convert
the primary analytical response for a sample to the corresponding determinand
concentration. If the samples and calibration standards are treated in exactly the same
manner (and provided that the materials used to prepare the calibration standards are
of adequate purity) no systematic error should arise from the calibration” (It has been
noted in 3.3.1 that any variations in the correctness of the calibration from batch to
batch will be manifested as between-batch random errors).
If, however, samples and calibration standards are treated differently, this can
represent a p.otentially serious source of error. Thus, for example, a method
prescribin.g some form of pre-concentration of the determinand from samples, but
employing direct calibration with standa$rds not taken through the pre-concentration
step, will give rise to negative bias if the’ pre-concentration recovery is less than 100 %.
In such cases, evidence should be obtained on the accuracy of the prescribed
calibration, or the difference in treatment of samples and standards eliminated.
Impurity of the material used to prepare calibration standards is, of course, another
potential cause of biased results.
Biased blank
d
The same considerations as in d] above appb to b&~~+ks, There isE, Hoover, another
source of bias arising f&m bllank correction, !f the water used for the bEank c.ontaEns the
determinand, results for samples wiEB be biased I&M by a,n equi&&nt an~unt W&SS a
correction for the determinand content of the blank water is a.pplied, ldealLy~ howe~er,~ a
source of blank water should be obtained, su.ck that, the: determinand emtent is
negligible in comparison with the concentration in s;~mpIes.
4 The quality system in water analysis
4.1 General
The quality system is the term used to describe the aspects which are intended to meet the clients’
requirements. The control of analytical errors, usually termed analytical quality control (AQC) is an
important component of the quality system. This clause summarizes the key issues which should be
addressed in designing a quality system.
For more detail and an authoritative account of quality assurance, readers should consult the standards
listed in clause 2, together with documentation provided by the various national accreditation bodies.
4.2 Quality system
4.2.1 .Aims and form of quality system
The laboratory should operate a quality system appropriate to the type, range, precision and volume of
tests that it undertakes. The quality system should be such as to ensure that the requirements of this
Technical Report are fully met on a continuing basis. All staff should be made fully aware of, and be
required to comply with, the documented quality system.
The ‘laboratory should possess a statement of the aims and general form of the laboratory’s quality
system, including the purpose of the quality manual and associated documentation.
@ IS0 ISO/TR 13530: 1997(E)
4.2.2 Quality manual
The quality system should be formalized in a quality manual which should be maintained and kept up-
to-date.
The person responsible for authorization and compilation of the quality manual should be identified. A
distribution list of the quality manual and identification of holders of controlled copies of the quality
manual should be included.
The quality manual should contain, for example the following items or equivalent:
1 Scope.
2 References.
3 Definitions.
4 Organization and management.
5 Quality system, audit and review.
Personnel.
7 Accommodation and environment.
Equipment and reference material.
9 Measurement, traceability and calibration.
10 Test methods.
Handling of calibration and test items.
Records.
Certificates and reports.
14 Subcontracting of calibration or testing.
Outside support services and supplies.
16 Complaints.
4.2.3 Quality management
The quality system should include a statement of the responsibilities and authority of the technical
manager and quality manager, and any appointed deputies.
The quality system should include a statement of the general arrangements for implementing each of
the quality manager’s and deputy’s responsibilities and the specific procedures for implementing these
responsibilities, or identification of laboratory documents containing such procedures.
4.2.4 Documentation
The quality system should include a statement of the quality manager’s responsibility in relation to
control and maintenance of documentation, including the quality manual, and of the specific
procedures for control, distribution, amendment, updating, retrieval, review and approval of all
documentation relating to the testing work of the laboratory.
@ IS0
ISO/I-R 13530:1997(E)
It should be made clear that laboratory staff should have ready access to all documentation, including
the quality manual test procedures, and all relevant standard specifications.
There should be an instruction forbidding alteration of laboratory documentation, except under
Instructions should also require adherence by all staff to the
conditions specified by management.
laboratory’s laid-down policies and procedures, except under clearly specified conditions.
The instruction should indicate clearly the circumstances under which departures from documented
policies and procedures or standard specifications are permitted. It should also indicate that departures
should be endorsed by management and their justification included in relevant records.
The quality system should include a statement of the specific procedures for dealing with situations
where staff have not followed documented policies, procedures and standard specifications as
required.
4.3 Quality policy
4.3.1 Management statement
The quality system should include a statement by senior management of the policy of the laboratory as
regards quality in all aspects of its work.
4.3.2 Quality systems
The quality system should include a statement of the intentions of the laboratory management
relation to q uality of service.
The quality system should include a statement that it is the responsibility of all staff to familiarize
themselves with the content of the quality manual and to comply with the policies and procedures laid
down in the quality manual and associated documentation.
These statements should be made on the authority of a senior executive, who has direct management
responsibility for the laboratory and who is at the highest level of management on which decisions are
taken on laboratory policy and resources. They should be authenticated by the signature, and legible
name and position, of the person concerned.
The policy statements should indicate:
- title of the person responsible for implementing the quality policy in the laboratory,
- title of the person having overall responsibility for control of quality and who advises on and monitors
all aspects of quality in the laboratory.
4.4 Organization and management
4.4.1 Organization
The quality system should include a statement to the identity and legal status of the laboratory
(including ownership and corporate position in relation to any parent organization or grouping of
companies) and a statement of the technical role of the laboratory (for example independent,
commercial, calibration/testing, or product quality control in support of a particular manufacturer).
A brief historical background should be included which is relevant to the standing of the laboratory,
together with a summary of the scope of operation and range of testing performed by the laboratory
and an inventory of tests performed by the laboratory.

ISWTR~ 13530: 1997(E)
4.4.2 Organization charts
Organization charts should be used showing:
technical manager, quality manager, and any deputies;
general lines of responsibility within the laboratory (including the relationship between
management, technical operations, quality control and support services);
the lines of responsibility within individual sections of the laboratory;
the relationship between the laboratory and any parent or sister organizations.
The appropriate chart should show that, for matters related to quality, the quality manager has direct
access to the highest level of management at which decisions are taken on laboratory policy or
resources, and to the technical manager.
4.4.3 Management
Details of job descriptions, qualifications, training and experience should be provided for:
technical manager;
quality manager;
other key laboratory managerial and technical posts.
Job descriptions should include:
title of job and brief summary of function;
person or functions to whom jobholder reports;
person or functions that report to jobholder;
key tasks that jobholder performs in the laboratory;
limits of authority and responsibility.
Technical manager - the quality system should include a statement that the post-holder has overall
responsibility for the technical operation of the laboratory and for ensuring that the quality system
requirements are met.
Quality manager - the quality system should include a statement that the post-holder has responsibility
for ensuring that the requirements for the quality system are met on a day-to-day basis and that the
post-holder has direct access to the highest level of management at which decisions are taken on
laboratory policy or resources, and to the technical manager.
The quality system should include a statement of:
any special arrangements for management and other functions, in the event of the
absence of key staff;
method whereby the laboratory makes all staff aware of the extent and limitations of
their responsibility;
laboratory policy with respect to influences or inducements that might adversely affect
the judgement of staff or the result of their work;

@ IS0
ISO/TR 13530: 1997(E)
actions to be taken by staff on encountering such influences or inducements;
policy and general arrangements for en suring the protection of proprietary
laboratory
of site security.
rights and information, and for other aspects
4.4.4 Staff qualifications and training
The quality system should include a statement of the laboratory’s general criteria for engagement of
staff and their assignment to respective duties and list the relevant academic and/or professional
qualifications, training and experience of key managerial, technical and other staff.
the laboratory’s procedures for defining in writing
The q uality system shou which ~ members of staff are authorized to use equip Iment or perform specific calibrations or tests
The quaMy ,system should include a statemen!& &the) Faboratory’s policy for the use of staff undergoing
training including their supervision.
statement as to the maintenance, a~c~ib$lE~ and location of all
The qualIi system should include. a
records relating to staff competence, q,uaIifications, training and experience.
4.5 Testiig environment
4.5.1 Laboratory testing environment
Samp lies, reage nts and stan dards should be sto Ired so as to ensure their integrity. The laboratory should
loss of identity.
guard against d eterioration, contamination and
Special care may need to be taken in some laboratories, for example those involved in trace a.nalysis,. ln
such cases, .it would be expected to see physical separation of high level and tow leveE work. Where
special areas are set aside for trace analysis, access to these areas should be restricted, and the type of
work undertaken carefully controlled.
Staff should be aware of:
the intended use of a particular area;
the restrictions imposed on working within such areas;
the reasons for imposing such restrictions.
Specific procedures for environmental conditions, for example the need for air-conditioning, required
by particular categories of tests, and the laboratory’s general arrangements for providing such
conditions and for dealing with disturbances of environmental laboratory conditions should be
established.
4.5.2 Iuboratory housekeeping
The quality system should include a general statement containing an instruction to staff to maintain
good ahousekeeping throughout the laboratory and where appropriate, to adopt special procedures.
4.53 Saff accommodation and conditions
The quality system should include a statement of laboratory’s intention to provide accommodation and
conditions for all staff, conducive to the proper performance of their respective duties.
4.6 Equipment and reference material
4.6.1 General
The quality should include an operating programme for the maintenance and calibration of
system
equipment used in the laboratory.
The quality system should include a statement of the use of reference material (a stable and homogene-
ous material or substance, one or more properties of which are sufficiently well established to be used
for the calibration of apparatus, the assessment of a measurement method or for assigning values to
materials).
4.6.2 General service equipment
General service equipment should only be maintained by cleaning and safety checks as necessary.
Calibrations or performance checks will be necessary where the setting can significantly affect the test
or analytical result (for example, the temperature of a muffle furnace or constant temperature bath.)
4.63 Volumetric equipment
The correct use of volumetric equipment is critical to analytical ‘measurements and it should be
maintained, calibrated and used in a manner consistent with the accuracy required of data. For the
highest accuracy, measurements can often be made by mass rather than by volume. The type used
(glass, polytetrafluoroethylene, etc.) cleaning, storage and segregation of volumetric equipment is
critical for the avoidance of contamination, particularly for trace analyses when leaching and adsorption
can be significant.
4.6.4 Balances and other measuring instruments
Periodic performance checks should be carried out at specified intervals on balances. Other instruments
may be checked (for example for response, stability and linearity of sources, sensors and detectors, the
separating efficiency of chromatographic systems, the resolution, alignment and wavelength accuracy
of spectrometers, etc.).
These checks are particularly important if errors are not easily detected as part of the routine quality
control system.
4.6.5 Computers and data processors
The computer systems should periodically be checked and maintained. The computer software should
be fully documented an d validated before use.
4.6.6 Defective equipment
Defective equipment should immediately be withdrawn from analytical work and not be returned until
re-calibrated, re-validated and re-authorized for use.
4.7 Receipt and handling of test samples
4.7.1 General
General arrangements are required for:
receipt, recording and handling of test items;
transfer of test items to and from the laboratory;
transfer of test items between different sections of the laboratory;
sampling, transport, storage, bonding and protection of items, as appropriate.
'11
@ IS0
ISO/TR 13530: 1997(E) j
4.7.2 Identification of test samples
There should be a system for identification of test items and any accessories.
4.7.3 Condltlon on receipt of test samples
The quality system should include a statement of the procedure for recording the condition of an item
on receipt and of the steps to be taken in conjunction with the client if the suitability of the item for
testing is in doubt.
4.7.4 Disposal of test samples
procedu res to be ado pted after completion of the
The quality system should include a statement of the
test for the retention and/or safe disposal of test items
4.0 Test reports
4.8.1 Control of test reports
The quality system should include a statement of laboratory policy and procedure for the content,
format, issue and transmission of certificates and test reports. The statement should cover the
procedures for the use of electronic data transfer as well as hard copy; instruction on minimum
information content of certificates and test reports including condensed or coded examples; instruction
on layout of test reports; and sample test report forms used by the laboratory.
4.8.2 Authorlzatlon of test reports
Instruction should be provided on checking and signature of test reports; and identification of approved
signatories (by list of named individuals or categories of staff) authorized to take technical responsibility
and legal responsibility for test reports on the laboratory’s behalf.
4.8.3 Validity of test reports
arising as to the
Instruction should be provided on action to be taken, in the event of doubts accu racy or
validity of results in any test reports issued.
4.8.4 Transmission of test results
Instruction should be provided in the procedures to be adopted when clients request transmission of
results by means other than as written test reports.
4.9 Records
4.9.1 Records system
The quality system should include a statement that the aim of the laboratory is to maintain records
systems such that all information of practical relevance to tests performed is available for a defined
time period.
The laboratory should ensure that this statement defines records systems that will enable them to
identify sources of any error and where appropriate, repeat the test under conditions close to the
original.
Arrangements for coordinating the
system through the laboratory and specific procedures for main-
taining records should be included.
lSO/TR 13530:1997(E)
4.9.2 Information recorded
The quality system should include a list of types of information held in the records and identification
and location of laboratory documents, or computerized records, holding each type of information.
The quality system should also include a statement on the use of worksheets or workbooks to record
various types of observation, calculation or other relevant information. Any changes to data should be
recorded, authorized and the original results retained.
This statement should indicate that provision should be made in all worksheets and workbooks to
record all the information required by the test method in order that. the test can be repeated under
similar conditions if necessary.
The quality system should include a statement of the procedure to be followed for recording, checking,
correcting, signing and countersigning observations and calculations.
4.9.3 Protection of records
The quality system should include instruction on protection of records, including those held on com-
puter.
4.9.4 Procedure for records
The quality system should include a statement of the procedure for retention of records including
observations and calculations, calibration certificates, test reports and test certificates. The period of
retention should be included.
4.10 Purchase of outside supplies and services
The quality system should include a statement of laboratory policy in relation to using outside supplies
and services of adequate quality with particular reference to goods certified by an accredited
certification system.
The quality system should also include a statement of general arrangements for ensuring that outside
supplies and services are of adequate quality for the laboratory’s purposes and that the necessary
checks, calibrations or other actions are made on purchased goods before use.
4.11 Subcontracting of tests
4.11.1 Subcontracting policy
statement of laboratory policy and general arrangements on the
The quality system should include a
subcontracting of tests.
This should emphasise that the laboratory’s policy is to carry out all tests and only to subcontract in
special circumstances. In the event that an unaccredited laboratory has to be used, the quality manual
should indicate that the subcontractor will be assessed against the requirements of the quality system
before use by the laboratory.
4.11.2 Subcontracting register
Identification of laboratory documents containing a register of all subcontractors used, records of
assessments performed where appropriate, and a record of all subcontracted work should be main-
tained.
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4.12 Diagnostics and corrective actions
The quality system should include a statement of laboratory policy on handling of complaints and
anomalies. The action to be followed, and the records to be made, by staff who are authorized and in
the first instance receive complaints or identify anomalies should be included.
Laboratory documents containing comprehensive records of complaints and anomalies and their
handling should be identified.
the procedures for analysing the records and
The quality system should include a statement of
proposing improvements to the quality system by the quality manager.
4.13 Quality audit and quality system review
4.13.1 Purpose
The quality system should include a statement of the laboratory’s aims in relation to quality audit and
review.
Audits (periodic checks carried out by or on behalf of management) should be ensured so that the
laboratory’s policies and procedures as set out in the quality manual are being followed. All activities
and responsibilities covered by the quality system, including the performance of tests, should be
audited.
Audits should be performed as frequently as is necessary but the programme should~ ensure that each
aspect of the quality system is examined.
Review (examination of the quality system by or on behalf of mana,gement) should be ensured so that
the quaFity system complies with the quality standards on a continuing basis.
Reviews .should be conducted as frequently as is necessary.
4.13.2 Responsibility
The quality system should include a statement of the responsibilities of the quality manager and any
appointed audit officers or deputies in relation to the planning, organization and conduct of quality
audits.
The laboratory should indicate who has been appointed as audit officer and that it is the policy to
choose an officer who is independent of the specific activities being audited. Laboratory staff are not
permitted to audit their own activities.
The quality system should include a statement indicating that it is the responsibility of the quality
manager to verify that all corrective actions required by audits have been completed and that reviews
care recorded in the quality system.
4.13.3 Implementation
‘The quality system
should include a statement of general arrangements for quality audit and quality
system review.
Mcluded should also be a summary of any internal data-monitoring carried out by the laboratory, as
.patt of its quality system and a summary of the scope of any external organization performing quality
audit or assessment of the laboratory.
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4.13.4 Planning and documentation
Laboratory documentation containing records of the planning, implementation and outcome of the
activities referred to in 4.13.3 should be identified.
The quality system should include samples of forms used by the laboratory’s programme for internal
quality audit, for quality system review, and where appropriate, for external quality audits and as-
sessments.
4.13.5 Quality control systems
The quality system should include a statement of general arrangements for implementing checks on
the quality of results provided to clients by the use of internal quality control schemes, proficiency
testing, interlaboratory comparisons, reference materials, replicate testing and retesting.
5 Performance characteristics of analytical systems
5.1 General
After the analytical requirements (see clause 6) have been established, the establishment of an
appropriate analytical system (see clause 7) is made easier if adequate performance data are available
. for the analytical system of interest.
The description of each of the characteristics listed below should be provided whenever possible. The
first three are intended to give a qualitative impression of the procedure and the applications for which
it is known to be suitable and can be of value in deciding whether it is worth consideration. The
remaining items are all quantitative performance characteristics.
5.2 Substance determined
efinition should be given of the forms of the substance that are determined by the procedure
A clear d
when necessary to avoid ambiguity, those forms that are not capable of dete rminati on.
and also,
5.3 Types of sample
The types of sample for which the system has been evaluated and is known to be suitable should be
stated. If necessary they may be distinguished from types of samples for which the procedure may be
adequate, but for which the analyst should carry out appropriate tests before deciding on its suitability.
5.4 Basis of system
A brief and clear statement of the system should be given that summarizes the principles of the
procedure and describes any instrumental techniques utilized.
5.5 Range of application
The range of application corresponds to the lowest and highest concentrations for which tests of
precision and bias have been carried out using the system without modification. Where an extension
can be used to enable the examina
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