SIST EN 13804:2002

SLOVENSKI STANDARD
SIST EN 13804:2002
01-september-2002
äLYLOD'RORþHYDQMHHOHPHQWRYYVOHGRYLK.ULWHULML]YHGEHVSORãQDQDYRGLODLQ
SULSUDYDY]RUFD
Foodstuffs - Determination of trace elements - Performance criteria, general
considerations and sample preparation
Lebensmittel - Bestimmung von Elementspuren - Leistungskriterien, allgemeine
Festlegungen und Probenvorbereitung
Produits alimentaires - Dosage des éléments traces - Criteres de performance,
généralités et préparation des échantillons
Ta slovenski standard je istoveten z: EN 13804:2002
ICS:
67.050 Splošne preskusne in General methods of tests and
analizne metode za živilske analysis for food products
proizvode
SIST EN 13804:2002 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 13804:2002

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SIST EN 13804:2002
EUROPEAN STANDARD
EN 13804
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2002
ICS 67.050
English version
Foodstuffs - Determination of trace elements - Performance
criteria, general considerations and sample preparation
Produits alimentaires - Dosage des éléments traces - Lebensmittel - Bestimmung von Elementspuren -
Critères de performance, généralités et préparation des Leistungskriterien, allgemeine Festlegungen und
échantillons Probenvorbereitung
This European Standard was approved by CEN on 20 March 2002.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2002 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13804:2002 E
worldwide for CEN national Members.

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SIST EN 13804:2002
EN 13804:2002 (E)
Contents
page
Foreword.3
Introduction .4
1 Scope .4
2 Normative references .4
3 Terms and definitions.5
4 Performance characteristics.7
5 Sampling.7
6 Sample preparation .7
7 Specific requirements for analysis of trace elements .10
8 Laboratory Quality standards.12
9 Expression of results .13
10 Test Report .13
Bibliography .14
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SIST EN 13804:2002
EN 13804:2002 (E)
Foreword
This document EN 13804:2002 has been prepared by Technical Committee CEN/TC 275 "Food analysis – Hori-
zontal methods", the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an identical text or
by endorsement, at the latest by November 2002, and conflicting national standards shall be withdrawn at the latest
by November 2002.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following coun-
tries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,
France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Swe-
den, Switzerland and the United Kingdom.
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Introduction
The Working Group CEN/TC275/WG10 – Trace Elements (Heavy Metals) selects and elaborates methods of
analysis of trace elements in foodstuffs.
There are many methods of analysis for the determination of trace elements in foodstuffs which have been vali-
dated and published; the analyst is often required to make a choice between several established methods all of
which purport to be applicable to the same analyte/matrix combination. The Working Group decided to establish
specific criteria to guide the analyst in the selection between several methods of analysis. As a general rule, ana-
lysts should give preference to methods of analysis which comply with the provisions given in clauses 1 and 2 of
the annex to [1], with the Decision in [9], and with the General Principles for Methods of Analysis of the Codex Ali-
mentarius Commission (CAC), as defined in the CAC Procedural Manual and further developed in the ”criteria ap-
proach“ to methods of analysis developed by the Codex Committee of Methods of Analysis and Sampling
(CCMAS).
The performance criteria laid down in this European Standard are based on published data or collected from official
reports on European interlaboratory studies. When these performance characteristics are absent or not available,
the criteria were established based on the experience and opinions of the experts of CEN/TC275/WG10.
The criteria included in this European Standard have also been used as a guidance in the Working Group 10 for
the selection of specific methods of analysis of trace elements to be standardised.
In addition, the Working Group 10 also decided to provide some general information on sample handling and sam-
ple preparation, laboratory equipment, apparatus, reagents, glassware, etc., which are applicable to the selected
methods.
General sample preparation procedures are specified, as well as examples for some foodstuffs.
1 Scope
This European Standard specifies performance criteria for the selection of methods of analysis of trace elements in
foodstuffs.
It provides general considerations about the special requirements on sample preparation, apparatus, equipment
and reagents for trace elements analysis.
In selecting a method of analysis for a specific food matrix, the analyst should give preference to any method which
has been developed by the appropriate vertical Technical Committee rather than using a method which has been
developed by the horizontal Technical Committee CEN/TC 275/WG 10. However it is the responsibility of the ana-
lyst to determine whether an applicable vertical standard has been published.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For
dated references, subsequent amendments to or revisions of any of these publications apply to this European
Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the
publication referred to applies (including amendments).
ISO 5725-1:1994, Accuracy (trueness and precision) of measurement methods and results – Part 1: General prin-
ciples and definitions.
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ISO 5725-2:1994, Accuracy (trueness and precision) of measurement methods and results – Part 2: Basic method
for the determination of repeatability and reproducibility of a standard measurement method.
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories.
3 Terms and definitions
For the purposes of this European Standard, the following terms and definitions apply.
3.1
method validation
process of acquiring a set of data indicating the accuracy and precision that a method is capable of producing for
specified analytes and sample types
3.2
precision
closeness of agreement between independent test results obtained under stipulated conditions [ISO 5725-1:1994]
3.3
repeatability
precision under repeatability conditions [ISO 5725-1:1994]
3.4
repeatability conditions
conditions where independent tests results are obtained with the same method on identical test items, in the same
laboratory, by the same operator, using the same equipment within short intervals of time [ISO 5725-1:1994]
3.5
reproducibility
precision under reproducibility conditions [ISO 5725-1:1994]
3.6
reproducibility conditions
conditions where tests results are obtained with the same method on identical test items in different laboratories
with different operators using different equipment [ISO 5725-1:1994]
3.7
RSD
r
(relative within laboratory standard deviation): precision characteristic which relates to the within laboratory variabil-
ity of a method. It is the standard deviation, expressed as a percentage of the mean, obtained under repeatability
conditions. It is given by the following formula:
s
r
RSD =·100% (1)
r
x
3.8
RSD
R
(relative between laboratory standard deviation): precision characteristic which relates to the between laboratory
variability of a method. It is the standard deviation, expressed as a percentage of the mean, obtained under repro-
ducibility conditions. It is given by the following formula:
s
R
(2)
RSD =·100%
R
x
3.9
Ho
r
(Horrat index for repeatability): the observed RSD divided by the RSD estimated from the Horwitz equation using
r R
the assumption r = 0,66 R
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3.10
Ho
R
(Horrat index for reproducibility): the observed RSD , divided by the RSD calculated by the Horwitz equation
R R
3.11
trueness
closeness of agreement between the average value obtained from a large series of test results and an accepted
reference value [ISO 5725-1:1994]
3.12
practicability
non-standard characteristic of an analytical procedure. It is dependent of the scope of the method, and is deter-
mined by requirements such as sample throughput and costs [9]
3.13
applicability
list of the commodities for which the candidate method can be applied as presented or with minor modifications [9]
3.14
specificity
ability of the method to distinguish between the analyte of interest and other substances present in the sample [9]
3.15
limit of detection
smallest measured content, from which it is possible to deduce the presence of the analyte with reasonable statisti-
cal certainty. The limit of detection is numerically equal to three times the standard deviation of the mean of blank
determinations (n > 20) [9]
3.16
limit of quantification
lowest content of the analyte which can be measured with reasonable statistical certainty. If both accuracy and pre-
cision are constant over a concentration range around the limit of detection, then the limit of quantification is nu-
merically equal to six times the standard deviation of the mean of blank determinations (n > 20) [9]
3.17
reference material (RM)
material or substance one or more of whose properties are sufficiently homogeneous and well established to be
used for the calibration of an apparatus, the assessment of a measurement method, or for assigning values to the
materials [4]
3.18
certified reference material (CRM)
reference material, accompanied by a certificate, one or more of whose property values are certified by a proce-
dure which establishes its traceability to an accurate realisation of the unit in which the property values are ex-
pressed, and for which each certified value is accompanied by an uncertainty at a stated level of confidence [4]
3.19
blank
solution resulting of executing the analytical procedure in all respects apart from the addition of the test portion [4]
3.20
laboratory sample
specific quantity of a product in the condition in which it was received at the laboratory for analysis
3.21
test sample
part taken from the laboratory sample that is representative in composition of the laboratory sample and has been
prepared in such a way that the eventual analysis can be carried out with a part of it
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3.22
test portion
representative quantity of the test sample used for the final analysis
3.23
sample preparation
operations carried out on the laboratory sample in order to obtain the test sample. For example, domestic prepara-
tion and separation of the edible part (washing, peeling, de-stoning, grinding), and if necessary, homogenisation,
drying or freeze drying
4 Performance characteristics
The following performance characteristics given in Table 1 are intended to be used as guidelines to help the ana-
lyst to select what is appropriate for his purpose. It is the responsibility of the analyst to undertake the selection.
The analyst should select a method which has been fully validated, i.e. with its performance characteristics based
on published data collected from official reports on interlaboratory studies on trace elements, which have been car-
ried out according to ISO 5725-1 and ISO 5725-2 or [8].
Table 1 — Performance characteristics
Parameter Value/Comment
Applicability As comprehensive and representative group of foodstuffs as possible
Horrat r and Horrat R index £ 2 in the validation collaborative trial (Some or-
Precision
ganisations may specify Horrat index < 2)
Specificity No significant cross interference permitted
Estimated by analysing CRM. The found mean should fall within the certified
Trueness
interval (excellent) or the two confidence interval should overlap (acceptable)
Limit of quantification Adequate to measure at the specification value
5 Sampling
Sampling methods are not included in this European Standard. Samples shall be representative of the parent
population. The procedures used for the acquisition, reduction and preservation of the sample all influence the reli-
ability of analytical results. The sampling of foodstuffs for trace elements analysis requires specific precautions in
order to avoid contamination or losses during handling and transport to the laboratory.
6 Sample preparation
6.1 General
Prepare sufficiently homogeneous samples in a way as usual for the preparation of foodstuffs in the normal house-
hold. Avoid contamination with elements to be determined, e.g. during operations such as grinding and cutting, to
the greatest possible extent.
6.2 Reagents, apparatus and equipment
No reagents and chemicals other than water shall be used in sample preparation. Ordinary tap water may be used
for washing some samples, e.g. vegetables. However, depending on the purposes of the analysis and the element
to be determined, it may be necessary to use purified water (see 7.1). Examples of apparatus required for sample
preparation are listed below:
 stainless steel or iron kitchen utensils (e.g. bread knife, meat knife, can opener, scissors, and also plastic
items as spoons);
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 plastic salad spinner;
 kitchen grinder;
 coffee grinder;
 stainless steel vegetable slicer;
 drying oven;
 freeze-drying apparatus with accessories;
 homogeniser.
Any equipment coming into direct contact with the sample shall be cleaned with detergent and hot water and finally
rinsed with de-ionised water.
Contamination problems arise when stainless steel or iron equipment is used for analysis of ele
...