SIST EN 13806:2002

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Lebensmittel - Bestimmung von Elementspuren - Bestimmung von Quecksilber mit Atomabsorptionsspektrometrie (AAS)-Kaltdampftechnik nach DruckaufschlussProduits alimentaires - Dosage des éléments-traces - Dosage du mercure par spectrométrie d'absorption atomique par génération de vapeurs froides apres digestion sous pressionFoodstuffs - Determination of trace elements - Determination of mercury by cold-vapour atomic absorption spectrometry (CVAAS) after pressure digestion67.050Splošne preskusne in analizne metode za živilske proizvodeGeneral methods of tests and analysis for food productsICS:Ta slovenski standard je istoveten z:EN 13806:2002SIST EN 13806:2002en01-november-2002SIST EN 13806:2002SLOVENSKI
STANDARD



SIST EN 13806:2002



EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 13806August 2002ICS 67.050English versionFoodstuffs - Determination of trace elements - Determination ofmercury by cold-vapour atomic absorption spectrometry(CVAAS) after pressure digestionProduits alimentaires - Dosage des éléments-traces -Dosage du mercure par spectrométrie d'absorptionatomique par génération de vapeurs froides après digestionsous pressionLebensmittel - Bestimmung von Elementspuren -Bestimmung von Quecksilber mitAtomabsorptionsspektrometrie (AAS)-Kaltdampftechniknach DruckaufschlussThis European Standard was approved by CEN on 29 May 2002.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards 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 translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.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 STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2002 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 13806:2002 ESIST EN 13806:2002



EN 13806:2002 (E)2ContentspageForeword.31Scope.32Normative references.33Principle.34Reagents.45Apparatus and equipment.56Procedure.57Calculation.68Limit of quantification.69Precision.710Test report.8Annex A (informative)
Results of the interlaboratory tests.9Bibliography.11SIST EN 13806:2002



EN 13806:2002 (E)3ForewordThis European Standard has been prepared by Technical Committee CEN/TC 275 "Food analysis - Horizontalmethods", 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 orby endorsement, at the latest by February 2003, and conflicting national standards shall be withdrawn at the latestby February 2003.Annex A is informative.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.1 ScopeThis European Standard specifies a method for the determination of mercury in foodstuffs by cold-vapour atomicabsorption spectrometry (CVAAS) after pressure digestion.Specific foodstuffs for which European Standards exist are excluded from the scope of this horizontal EuropeanStandard. It is the task of the analyst to review if vertical standards exist.2 Normative referencesThis European Standard incorporates by dated or undated reference, provisions from other publications. Thesenormative references are cited at the appropriate places in the text, and the publications are listed hereafter. Fordated references, subsequent amendments to or revisions of any of these publications apply to this EuropeanStandard only when incorporated in it by amendment or revision. For undated references the latest edition of thepublication referred to applies (including amendments).EN 13804, Foodstuffs — Determination of trace elements — Performance criteria, general considerations andsample preparation.EN 13805, Foodstuffs — Determination of trace elements — Pressure digestion.3 PrincipleDetermination of mercury in the test solution by cold-vapour atomic absorption spectrometry (CVAAS) after pressuredigestion according to EN 13805.The test solution is transferred to the reaction vessel of the mercury analysis unit, and the mercury is reduced withdivalent tin or sodium borohydride and flushed into the cuvette of the AAS instrument using a carrier gas stream.The absorption at 253,7 nm (mercury line) is used as a measure of the mercury concentration in the cuvette. If theamounts of mercury in the test solution are very small, it is advisable to enrich the mercury expelled on agold/platinum gauze (amalgam technique) prior to determination in the cuvette.SIST EN 13806:2002



EN 13806:2002 (E)4WARNING — The use of this standard can involve hazardous materials, operations and equipment. Thisstandard does not purport to address all the safety problems associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applica-bility of regulatory limitations prior to use.4 Reagents4.1 GeneralThe concentration of the trace elements in the reagents and water used shall be low enough not to affect the re-sults of the determination.4.2 Hydrochloric acid, not less than 30 % (mass fraction), of approximately
(HCl) = 1,15 g/ml.4.3 Nitric acid, not less than 65 % (mass fraction), of approximately
(HNO3) = 1,4 g/ml.4.4 Diluted nitric acid.Mix nitric acid (4.3) and water in a proportion of 1 + 9 parts by volume as a minimum.4.5 Reducing agent4.5.1 GeneralTin(II) chloride or sodium borohydride may be used as the reducing agent, but it is not advisable to use the tworeagents alternately. Observe the instructions of the manufacturers of the apparatus.4.5.2 Tin(II) chloride solution with a concentration of 100 g/l.Dissolve 50 g of tin(II) chloride, SnCl2 · 2H2O in approximately 100 ml of hydrochloric acid (4.2) in a 500 ml volu-metric flask and dilute to the mark with water. Prepare a fresh solution.4.5.3 Sodium borohydride solution with a concentration of 30 g/l.Dissolve 3 g of sodium borohydride together with 1 g of sodium hydroxide pellets in water and dilute to 100 ml.Prepare a fresh solution daily and, when necessary, filter it before use.The concentration by mass of the reducing agent solutions may be varied to suit the system and the relevant infor-mation provided by the manufacturer of the apparatus shall be observed.WARNING — It is essential to observe the safety instructions for working with sodium borohydride. So-dium borohydride forms hydrogen with acids and this can result in an explosive air/hydrogen mixture. Apermanent extraction system shall be provided at the point where measurements are carried out.4.6 Potassium permanganate solution with a concentration of 40 g/l.Dissolve 0,4 g of potassium permanganate solution in water and dilute to 10 ml. P
...