SIST EN 13806-3:2025

SLOVENSKI STANDARD
01-maj-2025
Nadomešča:
SIST EN 13806:2002
Živila - Določevanje elementov v sledovih - 3. del: Določevanje celotnega živega
srebra v živilih z atomsko absorpcijo neposredno iz živila (elementarna analiza
živega srebra)
Foodstuffs - Determination of trace elements - Part 3: Determination of total mercury in
foodstuffs with atomic absorption directly from the foodstuff (elemental mercury analysis)
Lebensmittel - Bestimmung von Elementspuren - Teil 3: Bestimmung des
Gesamtquecksilbers in Lebensmitteln durch Atomabsorption direkt aus dem
Lebensmittel (Elementare Quecksilberanalyse)
Produits alimentaires - Dosage des éléments traces - Partie 3 : Dosage du mercure total
dans les produits alimentaires par absorption atomique directe (analyse du mercure
élémentaire)
Ta slovenski standard je istoveten z: EN 13806-3:2025
ICS:
67.050 Splošne preskusne in General methods of tests and
analizne metode za živilske analysis for food products
proizvode
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 13806-3
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2025
EUROPÄISCHE NORM
ICS 67.050 Supersedes EN 13806:2002
English Version
Foodstuffs - Determination of trace elements - Part 3:
Determination of total mercury in foodstuffs with atomic
absorption directly from the foodstuff (elemental mercury
analysis)
Produits alimentaires - Dosage des éléments-traces - Lebensmittel - Bestimmung von Elementspuren - Teil
Partie 3 : Dosage du mercure total dans les produits 3: Bestimmung des Gesamtquecksilbers in
alimentaires par absorption atomique directe (analyse Lebensmitteln durch Atomabsorption direkt aus dem
du mercure élémentaire) Lebensmittel (Elementare Quecksilberanalyse)
This European Standard was approved by CEN on 17 February 2025.

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 CEN-CENELEC 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 CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13806-3:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Principle . 5
5 Reagents . 6
6 Apparatus . 8
7 Sampling . 8
8 Procedure . 8
8.1 Preparations for measurement . 8
8.1.1 Sample carrier cleaning . 8
8.1.2 Sample weight . 9
8.2 Direct atomic absorption spectrometry using thermal decomposition . 9
8.2.1 General. 9
8.2.2 Instrument blank value . 9
8.2.3 Instrument calibration and calibration control . 10
8.2.4 Measurement . 12
8.3 Quality control . 13
9 Evaluation . 13
9.1 Calculation . 13
9.2 Limit of quantification . 13
9.3 Precision . 14
9.4 Reproducibility . 14
9.5 Trueness . 14
10 Test report . 15
Annex A (informative) Precision data . 16
Annex B (normative) Explanations and notes . 18
Bibliography . 20

European foreword
This document (EN 13806-3:2025) has been prepared by Technical Committee CEN/TC 275 “Food
analysis – Horizontal 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 September 2025, and conflicting national standards shall
be withdrawn at the latest by September 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 13806:2002.
The main changes compared to the previous edition are listed below:
— the document has been split up into three separate parts: EN 13806-1 covering the AAS-cold-vapour
technique, EN 13806-2 the AFS-cold-vapour technique and EN 13806-3 the solid sample AAS
technique;
— full technical revision to bring the technical realization up to date with the latest technology;
— Stabilization of the digest solution;
— Update of statistical data by new interlaboratory study.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United
Kingdom.
Introduction
This document has been developed in parallel with EN 13806-1 [2] and EN 13806-2 [3]. All three
methods were validated in parallel in interlaboratory studies with the same scope. They are statistically
compatible in performances. This allows the users of these documents to employ the most
appropriate/available method depending on the purpose of their studies. The statistical parameters of
these standards are presented in the respective documents.
1 Scope
This document specifies a method for the determination of total mercury (Hg) in foodstuffs using direct
atomic absorption spectrometry after thermal decomposition in an oxygen or air flow and concentration
by amalgam formation. The method is applicable for solid and liquid samples.
This method was tested in a interlaboratory study carried out on seven different materials with a mercury
concentration in the range from 0,005 mg/kg to 5,20 mg/kg and successfully validated in this range.
The following foodstuffs were analysed:
— Saithe (dried);
— Celery (dried);
— Wheat noodle powder;
— Wild mushrooms (dried);
— Pig liver (dried);
— Cacao powder;
— Tuna fish (dried).
The lower limit of the method’s applicability varies depending on the food matrix and the water content
of the foodstuff. It is a laboratory-specific value and is defined by the laboratory when calculating the
limit of quantification (see 9.2).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 13804, Foodstuffs - Determination of elements and their chemical species - General considerations and
specific requirements
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
4 Principle
The samples to be analysed are weighed directly - without pressure digestion - into suitable sample
containers and are thermally decomposed in the analyser system in an oxygen atmosphere at approx.
700 °C. The resulting reaction gases are catalytically cleaned together with the mercury vapour, and the
mercury is concentrated on a consecutive amalgamator. Subsequently, the mercury is released as atomic
vapour by fast heating up of the amalgamator, transferred into a system of measurement cuvettes and
quantified by absorption at 253,7 nm.
By the simultaneous use of measurement cuvettes of different lengths, a dynamic measurement range
over several orders of magnitude can be achieved.
The total content of mercury is understood as the content measured using this document. It is indicated
in mg/kg.
WARNING — The use of this method can involve the application of dangerous substances, actions or
equipment. Nevertheless, the method description cannot mention all dangers possibly involved in its
application. Each operator of the method is responsible for taking the appropriate safety precautions and
to respect the corresponding regulations.
5 Reagents
5.1 General
Unless otherwise specified, “solutions” are understood to be aqueous solutions.
The content of mercury in the chemicals and water shall be low enough not to affect the results.
5.2 Hydrochloric acid, ω = 30 % to 37 %, density = approx. 1,15 g/ml.
5.3 Nitric acid, ω = 65 % to 69 %, density = approx. 1,4 g/ml.
5.4 Diluted nitric acid
Nitric acid (5.3) + water, V + V , approx. 1 + 9.
1 2
5.5 Stabilization
The standard, calibration and zero-point solutions are stabilized with hydrochloric acid (5.2). It is
recommended to adjust the hydrochloric acid concentration to approx. ω = 1 % in the solutions.
Alternatively, other stabilizing reagents may be used (for details see the instructions of the instrument
manufacturer or [2]).
5.6 Mercury stock solution, e.g. ϱ = 1 000 mg/l.
The stock solution is commercially available. It is recommended to use certified stock solutions.
5.7 Mercury standard solution
The standard solution is prepared from the stock solution (5.6) by means of dilution (e.g. see Table 1).
For this purpose, fill approx. 5 ml of water into a 20 ml volumetric flask, add the necessary amount of
stabilizing acid (e.g. 0,6 ml hydrochloric acid (5.2)) and mix. After the mixture has cooled down to room
temperature, add the stock solution (5.6) and fill up to the mark with water.
The standard solution is stable for at least one month.
Table 1 — Example for the preparation of Hg standard solution in a 20 ml volumetric flask
Fill up to the
Standard solution Stabilization Initial solution
mark with
[Hg concentration]
water to
200 µl
Standard solution
600 µl hydrochloric acid
20 ml
Hg stock solution
(5.2)
[10 mg/l]
(5.6)
5.8 Mercury calibration solutions and zero-point solution
To produce the examples of calibration solutions and zero-point solution described in Table 2, a 20 ml
volumetric flask is filled with approx. 5 ml of water, the necessary amount of stabilizing acid added
according to Table 2, and mixed. After the mixture has cooled down to room temperature, pipette the
standard solution/calibration solution into the flask and fill up to the mark with water.
Table 2 — Example for the preparation of the Hg calibration solutions and zero-point solution in
20 ml volumetric flasks
Standard Fill up to
Zero-point/ calibration
Stabilization
solution/ the mark
solution
calibration with water
[Hg concentration]
solution to
Zero-point solution 600 µl hydrochloric acid (5.2) - 20 ml
600 µl hydrochloric acid (5.2) 2 000 µl 20 ml
Calibration solution 1
standard
[1 000 µg/l]
solution (5.7)
600 µl hydrochloric acid (5.2) 2 000 µl 20 ml
Calibration solution 2
calibration
[100 µg/l]
solution 1
600 µl hydrochloric acid (5.2) 2 000 µl 20 ml
Calibration solution 3
calibration
[10 µg/l]
solution 2
600 µl hydrochloric acid (5.2) 2 000 µl 20 ml
Calibration solution 4
calibration
[1 µg/l]
solution 3
The mercury calibration solutions and the zero-point solution are used to set up the calibration of the
instrument as specified under 8.2.3.2. For this purpose, they shall be prepared fresh.
NOTE Alternatively, appropriate, certified reference materials can be used for calibration.
5.9 Oxygen or air
The manufacturer’s instructions shall be taken into account, e.g. for the analytical purity.
6 Apparatus
6.1 General
All equipment and labware that come into direct contact with the sample and the solutions used, shall be
carefully pre-treated/cleaned according to EN 13804 to minimize contamination.
For the cleaning of glass and quartz glass equipment the following steps in particular are recommended:
rinsing with tap water, treating with a detergent solution, rinsing again with tap water and immersing
overnight or longer in diluted nitric acid (5.4). Finally, rinse the equipment with high-purity water and
dry them before use. Steam stripping with nitric acid is an effective cleaning method and is used regularly
in element trace analysis.
When preparing solutions, special care shall be taken to avoid contaminations. The volumetric flasks used
for the preparation of the solutions should be made of glass or quartz glass.
Due to the strong adsorption behaviour of mercury on vessel walls it is recommended to always reuse
the same flasks for each concentration of standard and calibration solution. Nevertheless, they shall be
cleaned before each use.
6.2 Elemental mercury analyser
Elemental mercury analyser with instrument control unit and sample containers made of suitable
materials (e.g. nickel, quartz glass or ceramic). The sample containers usually have a capacity of approx.
500 mg of solid sample or 500 µl, 1 000 µl and 1 500 µl of liquids. The instructions in Annex B shall be
observed.
6.3 Analytical balance, readability of at least 0,000 1 g.
For an automated transfer of the sample weights, it is recommended to link the balance to the Hg-
analyser’s control unit (6.2) via a data interface.
7 Sampling
The sampling procedure is not part of the analytical method specified in this document.
Sampling shall be carried out in such a way that there is no loss of or contamination with mercury.
8 Procedure
8.1 Preparations for measurement
8.1.1 Sample carrier cleaning
Mechanically remove any residues adhering to the sample containers. Sample containers made of quartz
glass may be pre-cleaned with diluted nitric acid (5.4) according to EN 13804. Sample containers made
from nickel are only cleaned of adhering residues mechanically.
Subsequently, rinse the sample carriers with water and decontaminate them in a muffle furnace
according to the manufacturers’ instructions, e.g. at approx. 600 °C for at least 15 min. Alternatively, the
sample carriers, without sample weight, could be decontaminated by measuring them in the mercury
analyser by the sample program.
After cleaning, store the sample carriers in a dust-protected place (e.g. in a covered glass petri dish).
Irrespective of the material they are made of, carefully cleaned sample carriers do not show any memory
effects.
8.1.2 Sample weight
The sample prepared according to EN 13804 is weighted directly in the pre-cleaned sample carrier. The
maximum sample quantity depends on the capacity of the sample carrier, the type of sample material and
the expected mercury content (further information under B.2). If the measured absorption value is
outside the calibration range, repeat the analysis with a lower sample weight. With small quantities
attention shall be paid to the homogeneity of the sample and the lowest possible sample weight of the
analytical balance. Solid samples cannot be diluted.
Typical sample weights for sample containers with a volume of approx. 0,5 ml:
Liquid, pasty samples (e.g. milk, 0,1 g to 0,5 g
meat, fruit)
Powdery samples (e.g. flour) 0,05 g to 0,15 g
Samples with high fat content (e.g. 0,05 g to 0,1 g
nuts, margarine)
When analysing samples with high water content, the sample weight may be increased to 0,5 g to 1 g. For
these samples preferably use sample containers with a capacity of 1 ml to 1,5 ml.
NOTE 1 Liquid samples can be applied, for example, to approx. 50 mg of a substrate with low mercury content
(e.g. sea sand, alumina, starch or flour with contents < 0,001 ng of mercury absolute).
Liquid samples should also be weighed in, to prevent insufficient inaccuracies due to sample viscosity
and dosing inaccuracies due to the sample type.
NOTE 2 Samples with high fat content can be coated with a substrate with low mercury content (e.g. sea sand or
alumina with contents < 0,001 ng of mercury absolute), in order to prevent them from squirting in the furnace
during the drying process. Alternatively, furnace programmes with slow heating rates can be used (see 8.2.4,
Table 5).
8.2 Direct atomic absorption spectrometry using thermal decomposition
8.2.1 General
Follow the manufacturer’s instructions with regard to the initial daily operation, stabilizing time and
measurement with the elemental mercury analyser.
8.2.2 Instrument blank value
For solid sample systems the instrument blank value (system blank value originating from measurements
of cleaned sample carriers) is determined every working day, and is deducted from all subsequent
quantifications.
To determine the instrument blank value, measure cleaned sample carriers (8.1.1) in the elemental
mercury analyser. If the absorptions are above a set value, e.g. 0,01, the sample carrier shall be cleaned
again. Discard the blank values measured after switching on and stabilizing the instru
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