SIST EN 15505:2009
(Main)Foodstuffs - Determination of trace elements - Determination of sodium and magnesium by flame atomic absorption spectrometry (AAS) after microwave digestion
Foodstuffs - Determination of trace elements - Determination of sodium and magnesium by flame atomic absorption spectrometry (AAS) after microwave digestion
This document specifies methods for the determination of sodium and magnesium in foodstuffs by flame atomic absorption spectrometry (AAS) after microwave digestion. Collaborative studies have been carried out (Annex A). The method is suitable for the determination of sodium not less than 1 500 mg/kg and magnesium not less than 250 mg/kg. Data for calcium is included for information (Annex B). The method is not applicable to wheat bran.
Lebensmittel - Bestimmung von Elementspuren - Bestimmung von Natrium und Magnesium mit Flammen-Atomabsorptionsspektrometrie (AAS) nach Mikrowellenaufschluss
Dieses Dokument legt Verfahren zur Bestimmung von Natrium und Magnesium in Lebensmitteln mit
Flammen-Atomabsorptionsspektrometrie (AAS) nach Mikrowellenaufschluss fest. Ringversuche wurden
durchgeführt (Anhang A). Das Verfahren ist für die Bestimmung von Natrium bei einer Konzentration von
mindestens 1 500 mg/kg Trockensubstanz und Magnesium von mindestens 250 mg/kg Trockensubstanz
geeignet. Zur Information sind Daten für Calcium enthalten (Anhang B). Das Verfahren ist nicht auf
Weizenkleie anwendbar.
Produits alimentaires - Dosage des éléments traces - Dosage du sodium et du magnésium par spectrométrie d'absorption atomique de flamme après digestion par micro-ondes
Le présent document prescrit des méthodes de dosage du sodium et du magnésium dans les produits
alimentaires par spectrométrie d’absorption atomique de flamme après digestion par micro-ondes. Des études
conjointes ont été réalisées (Annexe A). La méthode convient pour le dosage du sodium et du magnésium,
avec une teneur respective en matière sèche au moins égale à 1 500 mg/kg et 250 mg/kg. Les données
concernant le calcium sont incluses pour information (Annexe B). La méthode n’est pas applicable au son de
blé.
Živila - Določevanje elementov v sledovih - Določevanje natrija in magnezija z uporabo spektrometrije s plamensko atomsko absorpcijo (AAS) po mikrovalovnem razklopu
General Information
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.NURYDORYQHPUD]NORSXLebensmittel - Bestimmung von Elementspuren - Bestimmung von Natrium und Magnesium mit Flammen-Atomabsorptionsspektrometrie (AAS) nach MikrowellenaufschlussProduits alimentaires - Dosage des éléments traces - Dosage du sodium et du magnésium par spectrométrie d'absorption atomique de flamme après digestion par micro-ondesFoodstuffs - Determination of trace elements - Determination of sodium and magnesium by flame atomic absorption spectrometry (AAS) after microwave digestion67.050Splošne preskusne in analizne metode za živilske proizvodeGeneral methods of tests and analysis for food productsICS:Ta slovenski standard je istoveten z:EN 15505:2008SIST EN 15505:2009en,fr,de01-april-2009SIST EN 15505:2009SLOVENSKI
STANDARD
SIST EN 15505:2009
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 15505March 2008ICS 67.050 English VersionFoodstuffs - Determination of trace elements - Determination ofsodium and magnesium by flame atomic absorptionspectrometry (AAS) after microwave digestionProduits alimentaires - Dosage des éléments traces -Dosage du sodium et du magnésium par spectrométried'absorption atomique de flamme après digestion parmicro-ondesLebensmittel - Bestimmung von Elementspuren -Bestimmung von Natrium und Magnesium mit Flammen-Atomabsorptionsspektrometrie (AAS) nachMikrowellenaufschlussThis European Standard was approved by CEN on 7 February 2008.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 CEN 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 CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2008 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 15505:2008: ESIST EN 15505:2009
EN 15505:2008 (E) 2 Contents Page Foreword.3 1 Scope.4 2 Normative references.4 3 Principle.4 4 Reagents.4 5 Apparatus and equipment.6 6 Procedure.6 7 Calculation.7 8 Precision.7 9 Test report.8 Annex A (informative)
Results of the inter-laboratory tests.9 Annex B (informative)
Additional information on calcium.12 Bibliography.15
SIST EN 15505:2009
EN 15505:2008 (E) 3 Foreword This document (EN 15505:2008) 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 2008, and conflicting national standards shall be withdrawn at the latest by September 2008. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. SIST EN 15505:2009
EN 15505:2008 (E) 4 1 Scope This document specifies methods for the determination of sodium and magnesium in foodstuffs by flame atomic absorption spectrometry (AAS) after microwave digestion. Collaborative studies have been carried out (Annex A). The method is suitable for the determination of sodium not less than 1 500 mg/kg and magnesium not less than 250 mg/kg. Data for calcium is included for information (Annex B). The method is not applicable to wheat bran. 2 Normative references The following referenced documents are indispensable for the application 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 trace elements — Performance criteria, general considerations and sample preparation EN 13805, Foodstuffs — Determination of trace elements — Pressure digestion 3 Principle The samples are digested in closed vessels in a microwave oven in a mixture of nitric acid and hydrogen peroxide. The resulting solution is diluted with water, and the sodium and magnesium contents are determined by flame-AAS using matrix modifiers.
WARNING — The use of this standard may involve hazardous materials, operations and equipment. This standard does not purport to address all the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 4 Reagents 4.1 General Use only reagents and water, which shall have an element level low enough not to affect results. The use of certified stock solutions is advisable. 4.2 Nitric acid 4.2.1 Nitric acid, not less than 65 % of approximately mass concentration ρ(HNO3) = 1,4 g/ml.
In case of insufficient purity, it is necessary to purify the nitric acid in a distillation apparatus as described in EN 13805. 4.2.2 Diluted nitric acid solution 1, mass fraction w = 2,7 %
Dilute 42 ml nitric acid (4.2.1) to 1 000 ml with water. 4.2.3 Diluted nitric acid solution 2, mass fraction w = 0,65 %
Mix nitric acid (4.2.1) and water in a proportion minimum of 1 + 99 parts by volume. SIST EN 15505:2009
EN 15505:2008 (E) 5 4.3 Hydrochloric acid, mass fraction w = 37 %
4.4 Hydrogen peroxide, mass fraction w = 30 % 4.5 Cesium chloride solution (CsCl), for use in AAS analysis Dissolve 31,75 g of cesium chloride in water and dilute to 250 ml. The solution will be stable in a refrigerator for at least 6 months. 4.6 Lanthanum(III)oxide (La2O3) solution, for use in AAS analysis, 5 % (weight/volume) Weigh 14,66 g of lanthanum(III)oxide into a 250 ml beaker, moisten with 10 ml of water and add 62,5 ml of HCl (4.3). Transfer to a 250 ml volumetric flask and fill up with water. The solution will be stable in a refrigerator for one month. 4.7 Sodium solution 4.7.1 Sodium stock solution, mass concentration ρ(Na) = 1 000 mg/l
4.7.2 Sodium standard solution, mass concentration ρ(Na) = 10 mg/l
Dilute 1 ml of sodium stock solution (4.7.1) to 100 ml in a volumetric flask with 2,7 % nitric acid (4.2.2). The solution will remain stable for one month at room temperature. 4.8 Magnesium solution 4.8.1 Magnesium stock solution, mass concentration ρ(Mg) = 1 000 mg/l 4.8.2 Magnesium standard solution, mass concentration ρ(Mg) = 10 mg/l
Dilute 1 ml of magnesium stock solution (4.8.1) to 100 ml in a volumetric flask with 0,65 % nitric acid (4.2.3). The solution will remain stable for one month at room temperature. SIST EN 15505:2009
EN 15505:2008 (E) 6 5 Apparatus and equipment 5.1 General All glassware and plastic ware should be carefully cleaned and rinsed according to the procedure in EN 13804. 5.2 Laboratory microwave oven Check the microwave oven for delivered power according to the procedure in EN 13804. 5.3 Atomic absorption spectrometer 5.4 Element specific lamps For sodium and magnesium element specific lamps with wavelength of 589,0 nm and 285,2 nm respectively will apply. 5.5 Acetylene Use acetylene of appropriate quality. 5.6 Air 6 Procedure 6.1 Pre-treatment Homogenise the sample in accordance with the recommendations in EN 13804. If necessary, dry the sample in a way that does not affect the element contents, e.g. by freeze drying. 6.2 Sample preparation Use the test solution obtained by microwave oven digestion method according to EN 13805 for the determination of sodium and magnesium.
6.3 Dilution Pipette a suitable volume of the sample solution, add 5 % La-solution (4.6) and dilute this volume with 0,65 % nitric acid (4.2.3) so that the final concentration of Mg is within the linear range of measurement of the elements. In this example, the following ranges are selected for the standard curves; for Mg, 0,05 mg/l to 0,4 mg/l. The lowest point may be lower, if required by the concentrations of the sample solutions. Add 5 % of La-solution (4.6) to a final mass fraction of La of 1 % (e.g. 2 ml 5 % is diluted to 10 ml). Pipette a suitable volume of the sample solution, add 1 ml of Cs-solution (4.5) and dilute this volume with 2,7 % nitric acid (4.2.2) so that the final concentration of Na is within the range of measurement of the element. In this example, the following range is selected for the standard curve: 0,1 mg/l to 1,0 mg/l. The lowest point may be lower required by concentration of the sample solution. SIST EN 15505:2009
EN 15505:2008 (E) 7 6.4 Preparation of standard solution Prepare working standard solutions for Na of 0,1 mg/l, 0,25 mg/l, 0,5 mg/l, 0,75 mg/l and 1,0 mg/l from the Na standard solution (4.7.2). Add 0,5 ml, 1,25 ml, 2,5 ml, 3,75 ml and 5 ml to separate 50 ml volumetric flasks, add 1 ml of Cs-solution (4.5) and dilute to the mark with diluted nitric acid solution 1 (4.2.2). Prepare fresh solution daily. Prepare working standard solutions for Mg of 0,05 mg/l, 0,1 mg/l, 0,2 mg/l and 0,4 mg/l from the Mg standard solution (4.8.2). Add 0,25 ml, 0,5 ml, 1,0 ml and 2,0 ml to separate 50 ml volumetric flasks, add 10 ml of 5 % La-solution (4.6) and dilute to the mark with diluted nitric acid solution 2 (4.2.3). Prepare fresh solutions daily. 6.5 Settings for the atomic absorption spectrometer Before every determination, adjust the instrument as specified in the manufacturer’s operating manual. E
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.