prEN 13806-2
(Main)Foodstuffs - Determination of trace elements - Part 2: Determination of total mercury in foodstuffs by atomic fluorescence spectrometry (AFS) - Cold vapour technique after pressure digestion
Foodstuffs - Determination of trace elements - Part 2: Determination of total mercury in foodstuffs by atomic fluorescence spectrometry (AFS) - Cold vapour technique after pressure digestion
This document specifies a method for the determination of total mercury in foodstuffs by cold vapour atomic fluorescence spectrometry (AFS) after pressure digestion.
This method was tested in a collaborative study carried out in connection with the pressure digestion method EN 13805 on seven different materials with a mercury concentration in the range from 0,006 mg/kg to 5,38 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 applicabilitiy 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.
Lebensmittel - Bestimmung von Elementspuren - Teil 2: Bestimmung des Gesamtquecksilbers in Lebensmitteln mittels Atomfluoreszenzspektrometrie (AFS) - Kaltdampftechnik nach Druckaufschluss
Produits alimentaires - Dosage des éléments traces - Partie 2 : Dosage du mercure total dans les produits alimentaires par spectrométrie de fluorescence atomique (SFA) - Génération de vapeurs froides après digestion sous pression
Le présent document spécifie une méthode pour le dosage du mercure total dans les produits alimentaires par spectrométrie de fluorescence atomique (SFA) à vapeurs froides après digestion sous pression.
Cette méthode a été testée dans le cadre d’une étude interlaboratoires réalisée en lien avec l’EN 13805 relative à la méthode de la digestion sous pression, sur sept matériaux différents dans lesquels la concentration du mercure variait entre 0,006 mg/kg et 5,38 mg/kg, et a été validée pour ce domaine de concentration.
Les produits alimentaires suivants ont été analysés :
— Lieu noir (séché) ;
— Céleri (séché) ;
— Nouilles de blé en poudre ;
— Champignons sauvages (séchés) ;
— Foie de porc (séché) ;
— Cacao en poudre ;
— Thon (séché).
Le seuil d’applicabilité de la méthode varie en fonction de la matrice alimentaire et de la teneur en eau du produit alimentaire. Il s’agit d’une valeur spécifique au laboratoire, définie par celui-ci lors du calcul de la limite de quantification (voir 9.2).
Živila - Določevanje elementov v sledovih - 2. del: Določevanje celotnega živega srebra v živilih z atomsko florescenčno spektrometrijo (AFS) - Tehnika hladne pare po razklopu pod pritiskom
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-september-2023
Živila - Določevanje elementov v sledovih - 2. del: Določevanje celotnega živega
srebra v živilih z atomsko florescenčno spektrometrijo (AFS) - Tehnika hladne
pare po razklopu pod pritiskom
Foodstuffs - Determination of trace elements - Part 2: Determination of total mercury in
foodstuffs by atomic fluorescence spectrometry (AFS) - Cold vapour technique after
pressure digestion
Lebensmittel - Bestimmung von Elementspuren - Teil 2: Bestimmung des
Gesamtquecksilbers in Lebensmitteln mittels Atomfluoreszenzspektrometrie (AFS) -
Kaltdampftechnik nach Druckaufschluss
Produits alimentaires - Dosage des éléments traces - Partie 2 : Dosage du mercure total
dans les produits alimentaires par spectrométrie de fluorescence atomique (SFA) -
Génération de vapeurs froides après digestion sous pression
Ta slovenski standard je istoveten z: prEN 13806-2
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.
DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2023
ICS 67.050 Will supersede EN 13806:2002
English Version
Foodstuffs - Determination of trace elements - Part 2:
Determination of total mercury in foodstuffs by atomic
fluorescence spectrometry (AFS) - Cold vapour technique
after pressure digestion
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 275.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CEN 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.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 13806-2:2023 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 . 6
5 Reagents . 6
6 Apparatus . 9
7 Sampling .10
8 Procedure.10
8.1 Digestion, removal of nitrous gases and stabilization .10
8.2 Cold vapour atomic fluorescence spectrometry .10
8.2.1 Spectrometer settings .10
8.2.2 Cold vapour AFS determination .11
8.3 Quality control .11
9 Evaluation .11
9.1 Calculation .11
9.2 Limit of quantification .11
9.3 Precision .12
9.4 Reproducibility .13
9.5 Trueness .13
10 Test report .13
Annex A (informative) Explanations and notes .14
Bibliography .17
European foreword
This document (prEN 13806-2:2023) has been prepared by Technical Committee CEN/TC 275 “Food
analysis – Horizontal methods”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document will supersede 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 collaborative study;
— full editorial revision.
This document was developed by the “Element Analysis” working group of the Federal Office of Consumer
Protection and Food Safety (BVL) according to the German Food and Feed Act, Paragraph 64.
Introduction
1 2
This document has been developed in parallel with EN 13806-1:2023 [3] and EN 13806-3:2023 [4]. All
three methods were validated in parallel in collaborative 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.
Under preparation. Stage at the time of publication: prEN 13806-1:2023.
Under preparation. Stage at the time of publication: prEN 13806-3:2023.
1 Scope
This document specifies a method for the determination of total mercury in foodstuffs by cold vapour
atomic fluorescence spectrometry (AFS) after pressure digestion.
This method was tested in a collaborative study carried out in connection with the pressure digestion
method EN 13805 on seven different materials with a mercury concentration in the range from
0,006 mg/kg to 5,38 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 13804:2013, Foodstuffs - Determination of elements and their chemical species - General considerations
and specific requirements
EN 13805:2014, Foodstuffs - Determination of trace elements - Pressure digestion
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:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
4 Principle
Mercury (Hg) is determined by AFS-cold-vapour technique in the test solution obtained by performing
the pressure digestion process described in EN 13805:2014.
The test solution is transferred into the reaction vessel of the mercury analyser to reduce the oxidized
forms of mercury to elemental mercury with bivalent tin or sodium borohydride. The elemental mercury
is then flushed into the cuvette of the AAS instrument using a carrier gas stream. The absorption at the
mercury line of 253,7 nm is used to determine the mercury concentration. In case of very small quantities
of mercury in the test solution, it is recommended to use a technique capable to concentrate the stripped
mercury on a gold/platinum gauze (amalgam technique) prior to determination.”
The total content of mercury is understood as the content measured using this described method. It is
indicated in mg/kg or mg/l, depending on the samples type.
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 Ascorbic acid solution, ϱ = 100 g/l.
Dissolve 10 g of ascorbic acid in 100 ml of water.
The solution remains stable for a maximum of one week.
5.6 Reducing agent
5.6.1 Tin(II) chloride solution, e.g. ϱ = 100 g/l.
Dissolve 50 g of tin(II) chloride, SnCI • 2 H 0, in approx. 100 ml of hydrochloric acid (5.2) in a 500 ml
2 2
volumetric flask and fill up to the mark with water. The solution shall be prepared freshly before use.
NOTE 1 The required concentration of tin(II) chloride depends on the analysis system and the concentration of
nitric acid in the measurement solution. Too low concentrations of tin(II) chloride could lead to insufficient
recoveries.
NOTE 2 Tin(II) chloride ages quickly, visible in light yellow precipitates of tin(IV) oxides. In case of higher
concentrations of tin(II) chloride, these precipitates occur more frequently.
NOTE 3 If necessary, the tin(II) chloride solution can be flushed with argon gas in order to remove any possible
traces of mercury.
5.7 Carrier solution
Diluted hydrochloric acid (prepared from 5.2, e.g. ω = 3 %) is used as the carrier solution.
The mass concentration of the carrier solution can vary depending on the instrument. Observe the
respective information of the instrument manufacturer.
5.8 Stabilization
5.8.1 General
Potassium bromide/bromate reagent is recommended to stabilize the digestion, calibration, zero-point
and test solutions.
The potassium bromide/bromate reagent can be produced from the respective salts. Ampoules with
ready-mixed potassium bromide-potassium bromate solution are commercially available and can also be
used.
Alternative methods can also be used to avoid the interference resulting from the nitrous gases (see also
8.1) and to stabilize the mercury.
5.8.2 Example for preparation of a stabilizing reagent
5.8.2.1 Potassium bromate solution, ϱ = 5,56 g/l.
Dissolve 1,39 g of potassium bromate in 250 ml of water. A possible mercury contamination of the
potassi
...
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