EN 15505:2008

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
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

Results of the inter-laboratory tests.9 Annex B (informative)
Additional information on calcium.12 Bibliography.15
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

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

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

is the content of the element in the test solution, in milligram per litre; V
is the volume of the digestion solution after being made up, in millilitres; F
is the dilution factor of the test solution; m
is the initial sample mass, in grams. If necessary, subtract the concentration in the blank solution from the concentration of the sample solution, before the calculation is made. 8 Precision 8.1 General Details of an inter-laboratory trial on the precision of the method are summarized in Annex A. The values derived from this inter-laboratory test may not be applicable to concentration ranges and matrices other than those given. 8.2 Repeatability and reproducibility Repeatability is the absolute difference between two independent single test results (blind duplicate), obtained with the same method on identical test material in the same laboratory by the same operator using the same equipment within a short interval of time. This will in not more than 5 % of the cases exceed the values of r given in Table 1 to Table 2. Reproducibility is the absolute difference between two single test results, obtained with the same method on identical test material in different laboratories by different operators using different equipment. This will in not more than 5 % of the cases exceed the values of R given in Table 1 to Table 2. SIST EN 15505:2009

mg/kg R
mg/kg Broccoli 2 290 210 320 Carrot 3 540 330 420 White bread 8 260 570 1 040 Saithe fillet 2 030 210 350 Pork 1 480 77 280 Cheese 5 380 980 1 040
Table 2 — Mean values, repeatability limits and reproducibility limits for magnesium Sample x mg/kg r
mg/kg R
mg/kg Simulated diet (D) 665 70 129 Simulated diet (F) 618 76 120 Milk powder, freeze dried 859 51 111 Minced fish, freeze dried 749 50 144 Apple, dried 251 15 32 Chocolate cake, dried 284 16 32
9 Test report The test report shall specify: a) all information necessary for the complete identification of the sample; b) test method used, with reference to this document; c) test results obtained and the units in which they are specified; d) date when the analysis was finished; e) whether the requirement of the repeatability limit has been fulfilled; f) all operating details not specified in thi
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