SIST EN 14083:2003

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Lebensmittel - Bestimmung von Elementspuren - Bestimmung von Blei, Cadmium, Chrom und Molybdän mit Graphitofen- Atomabsorptionsspektrometrie (GFAAS) nach DruckaufschlussProduits alimentaires - Dosage des éléments traces - Dosage du plomb,du cadmium,du chrome et molybdene par spectrométrie d'absorption atomique en four graphite apres digestion sous pressionFoodstuffs - Determination of trace elements - Determination of lead, cadmium, chromium and molybdenum by graphite furnace atomic absorption spectrometry (GFAAS) 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 14083:2003SIST EN 14083:2003en01-junij-2003SIST EN 14083:2003SLOVENSKI
STANDARD



SIST EN 14083:2003



EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 14083April 2003ICS 67.050English versionFoodstuffs - Determination of trace elements - Determination oflead, cadmium, chromium and molybdenum by graphite furnaceatomic absorption spectrometry (GFAAS) after pressuredigestionProduits alimentaires - Dosage des éléments traces -Dosage du plomb,du cadmium,du chrome et molybdènepar spectrométrie d'absorption atomique en four graphiteaprès digestion sous pressionLebensmittel - Bestimmung von Elementspuren -Bestimmung von Blei, Cadmium, Chrom und Molybdän mitGraphitofen- Atomabsorptionsspektrometrie (GFAAS) nachDruckaufschlussThis European Standard was approved by CEN on 18 December 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,Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and UnitedKingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2003 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 14083:2003 ESIST EN 14083:2003



EN 14083:2003 (E)2ContentspageForeword.31Scope.32Normative references.33Principle.34Reagents.45Apparatus and equipment.56Procedure.67Calculation.78Limit of quantification.79Precision.810Test report.9Annex A (informative)
Results of the interlaboratory test.10Bibliography.14SIST EN 14083:2003



EN 14083:2003 (E)3ForewordThis document (EN 14083:2003) 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 orby endorsement, at the latest by October 2003, and conflicting national standards shall be withdrawn at the latestby October 2003.Annex A is informative.According to the CEN/CENELEC Internal Regulations, the national standards organizations of the followingcountries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal,Slovakia, Spain, Sweden, Switzerland and the United Kingdom.1 ScopeThis European Standard specifies a method for the determination of lead, cadmium, chromium and molybdenum infoodstuffs by graphite furnace atomic absorption spectrometry (GFAAS) after pressure digestion.Specific foodstuffs for which European Standards exist are excluded from the scope of this horizontal EuropeanStandard. The analyst shall 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 and samplepreparation.EN 13805, Foodstuffs - Determination of trace elements - Pressure digestion.3 PrincipleDetermination of the elements in the test solution by graphite furnace atomic absorption spectrometry (GFAAS) [1],[2], [4] after pressure digestion according to EN 13805.WARNING — 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 theapplicability of regulatory limitations prior to use.SIST EN 14083:2003



EN 14083:2003 (E)44 Reagents4.1 GeneralThe concentration of the trace elements in the reagents and water, used shall be low enough not to affect theresults of the determination.4.2Hydrochloric acid, not less than 25 %, (mass fraction), having a density of approximately(HCl) = 1,13 g/ml and suitable for trace element analysis.4.3Nitric acid, not less than 65 %, (mass fraction), having a density of approximately (HNO3) = 1,4 g/ml andsuitable for trace element analysis.4.4 Stock solutionsNOTEThe stock solutions for lead, cadmium, chromium and molybdenum can be prepared from metals or metal salts.They can be commercially available also. It is advisable to use certified stock solutions. The preparation of stock solutions aregiven as an example in the following:4.4.1 Lead stock solution, with a lead concentration of 1 000 mg/l.Dissolve 1,598 g of lead nitrate (Pb(NO3)2) in nitric acid 1% (10 ml according to 4.3 diluted with water to 1 000 ml)and make up with nitric acid 1 % to 1 000 ml.4.4.2 Cadmium stock solution, with a cadmium concentration of 1 000 mg/l.Dissolve 1,000 g of cadmium metal in a minimum amount of hydrochloric acid 1 % (10 ml according to 4.2 anddiluted with water to 1 000 ml) and make up to 1 000 ml with 1 % (parts by volume) hydrochloric acid.4.4.3 Chromium stock solution, with a chromium concentration of 1 000 mg/l.Dissolve 3,735 g of potassium chromate (K2CrO4) in water and make up with water to 1 000 ml.4.4.4 Molybdenum stock solution, with a molybdenum concentration of 1 000 mg/l.Dissolve 1,840 g of ammonium heptamolybdate((NH4)6Mo7O24 . 4H2O) in ammonia solution 1% (10 ml ammoniasolution of min 25 %, (NH3) = 0,91 g/ml, diluted with water to 1 000 ml)) and make up with ammonia solution 1 % to1 000 ml.4.5 Calibration solutionsDilute the stock solutions to the concentrations needed for calibration; the concentrations shall be chosen so as notto exceed the linear range of the calibration function. It is recommended to use a minimum of 3 calibration solutionswith different concentrations. The concentration of acid in the calibration solutions shall be equal to that in the testsolution (see EN 13805).4.6 Zero member compensation solutions, which shall contain water and an amount of acid which isequal to the acid concentration in the test solution.SIST EN 14083:2003



EN 14083:2003 (E)54.7 Modifier4.7.1 GeneralThe examples of modifiers listed below may vary considerably both in combination and in concentration. Therecommendation of the manufacturer of the apparatus shall be taken as a starting point for subsequentoptimisation. Instead of the solutions according to 4.7.2 to 4.7.5, commercial magnesium nitrate and palladiumnitrate solutions may be used.NOTEThe analyst should be aware that the specific use of modifiers for a given element should be applied duringestablishment of the optimum furnace temperature program.4.7.2 Magnesium nitrate solutionDissolve 0,25 g of magnesium nitrate hexahydrate (Mg(NO3)2 × 6H2O) in 100 ml of water.4.7.3 Palladium/magnesium nitrate solutionDissolve 0,075 g of palladium in 2 ml of hot nitric acid (4.3), dilute to 25 ml with water, add 0,05 g ofMg(NO3)2 × 6H2O and make up to 50 ml with water.4.7.4 Ammonium phosphate/magnesium nitrate solutionDissolve 0,5 g of ammoniumdihydrogenphosphate (H2NH4PO4)
in water, add 0,05 g of Mg(NO3)2 × 6H2O and 1 mlnitric acid 4.3 and make up to 50 ml with water.4.7.5 Palladium/ascorbic acid solutionSolution A: add 500 ml of hydrochloric acid (4.2) to 1 ml of a palladium stock solution containing 10 g of palladiumper litre and make up to 10 ml.Solution B: dissolve 1 g ascorbic acid in 100 ml of water.Prepare the palladium/ascorbic acid solution by mixing one part by volume of solution A with one part by volume ofsolution B.5 Apparatus and equipment5.1 GeneralTo minimise the contamination, all apparatus which comes into direct contact with the sample and the solutionsshould be carefully pre-treated according to EN 13804.5.2 Atomic absorption spectrometerWith background correction (Zeeman correction is recommended), graphite furnace supplied with argon and with ameasurement recording system.5.3 Graphite tubesRecommendation, pyrolytically coated tubes with or without L'vov platform.SIST EN 14083:2003



EN 14083:2003 (E)65.4 Automatic sample injector5.5 Element-specific lamps (hollow-cathode or electrodeless discharge lamps) for lead, cadmium, chromiumand molybdenum.6 Procedure6.1 Sample preparationThe test solution obtained by the pressure digestion method according to EN 13805 may be used for thedetermination without further treatment.6.2 Atomic absorption spectrometry (graphite furnace AAS)6.2.1 Spectrometer settingsBefore every determination, adjust the instrument as specified in the manufacturer's operating manual. Thendetermine an optimum test schedule (if possible using a sample matrix), taking into account, in particular, ofparameters such as decomposition temperature and time, atomization temperature and time. In addition matrixmodif
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