DIN EN 15763-2010 Foodstuffs - Determination of trace elements - Determination of arsenic cadmium mercury and lead in foodstuffs by inductively coupled plasma mass spectrometry (IC.pdf

1、April 2010 Translation by DIN-Sprachendienst.English price group 12No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS

2、67.050!$aX4“1625317www.din.deDDIN EN 15763Foodstuffs Determination of trace elements Determination of arsenic, cadmium, mercury and lead in foodstuffs byinductively coupled plasma mass spectrometry (ICP-MS) after pressuredigestionEnglish translation of DIN EN 15763:2010-04Lebensmittel Bestimmung von

3、 Elementspuren Bestimmung von Arsen, Cadmium, Quecksilber und Blei in Lebensmitteln mit induktivgekoppelter Plasma-Massenspektrometrie (ICP-MS) nach DruckaufschlussEnglische bersetzung von DIN EN 15763:2010-04Produits alimentaires Dosage des lments traces Dosage de larsenic, du cadmium, du mercure e

4、t du plomb par spectromtrie dmissionavec plasma induit par haute frquence et spectromtre de masse (ICP-MS) aprsdigestion sous pressionTraduction anglaise de DIN EN 15763:2010-04www.beuth.deIn case of doubt, the German-language original shall be considered authoritative.Document comprises 20 pages04.

5、10 DIN EN 15763:2010-04 2 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee CEN/TC 275 “Food analysis Horizontal methods” (Secretariat: DIN, Germany). The responsible German body involved in its preparation was the Normenausschuss Lebensm

6、ittel und landwirtschaftliche Produkte (Food and Agricultural Products Standards Committee), Working Committee NA 057-01-09 AA Elemente und ihre Verbindungen. EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15763 December 2009 ICS 67.050 English Version Foodstuffs - Determination of trace eleme

7、nts - Determination of arsenic, cadmium, mercury and lead in foodstuffs by inductively coupled plasma mass spectrometry (ICP-MS) after pressure digestion Produits alimentaires - Dosage des lments traces - Dosage de larsenic, du cadmium, du mercure et du plomb par spectromtrie dmission avec plasma in

8、duit par haute frquence et spectromtre de masse (ICP-MS) aprs digestion sous pression Lebensmittel - Bestimmung von Elementspuren - Bestimmung von Arsen, Cadmium, Quecksilber und Blei in Lebensmitteln mit induktiv gekoppelter Plasma-Massenspektrometrie (ICP-MS) nach Druckaufschluss This European Sta

9、ndard was approved by CEN on 7 November 2009. 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. Up-to-date lists and bibliographical references concernin

10、g such national standards 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 translation under the responsibility of a CEN member into its own la

11、nguage and notified to the CEN Management Centre has the same status as the official 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,

12、 Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN Al

13、l rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 15763:2009: EEN 15763:2009 (E) 2 Contents Page Foreword 31 Scope 42 Normative references 43 Principle 44 Reagents .45 Apparatus and equipment 66 Procedure .67 Calculation . 108 Analytical q

14、uality control . 119 Limit of quantification 1110 Precision 1111 Test report . 13Annex A (informative) Results of the collaborative test . 14Bibliography . 18DIN EN 15763:2010-04 EN 15763:2009 (E) 3 Foreword This document (EN 15763:2009) has been prepared by Technical Committee CEN/TC 275 “Food anal

15、ysis - 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 June 2010, and conflicting national standards shall be withdrawn at the latest

16、by June 2010. 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 standard

17、s 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, Portu

18、gal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN 15763:2010-04 EN 15763:2009 (E) 4 1 Scope This European Standard specifies a method for the determination of arsenic, cadmium, mercury and lead in foodstuffs by inductively coupled plasma mass spectrometry (I

19、CP-MS). The collaborative study included foodstuffs such as carrots, fish homogenate, Mushrooms (CRM), graham flour, a simulated diet E (CRM), scampi, mussel and a Tort-2 CRM having an arsenic mass fraction ranging from 0,06 mg/kg to 21,5 mg/kg dry matter (d. m.), cadmium ranging from 0,03 mg/kg to

20、28,3 mg/kg d. m., mercury ranging from 0,04 mg/kg to 0,56 mg/kg d. m. and lead from 0,01 mg/kg to 2,4 mg/kg d. m. 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 refere

21、nces, the latest edition of the referenced document (including any amendments) applies. EN 13805, Foodstuffs Determination of trace elements Pressure digestion 3 Principle The test solution, obtained by pressure digestion, is nebulised and the aerosol transferred to a high frequency inductively coup

22、led argon plasma. The high temperature of the plasma is used to dry the aerosol and to atomise and ionise the elements. The ions are extracted from the plasma by a set of sampler and skimmer cones and transferred to a mass spectrometer where the ions are separated by their mass/charge ratio and dete

23、rmined by a pulse-count and/or analogue detector. WARNING The use of this method may involve hazardous materials, operations and equipment. This method does not purport to address all the safety problems associated with its use. It is the responsibility of the user of this method to establish approp

24、riate safety and health practices and determine the applicability of regulatory limitations prior to use. 4 Reagents 4.1 General The concentration of the trace elements in the reagents and water used shall be low enough not to affect the results of the determination. Using a multielemental method of

25、 high sensitivity like ICP-MS, the control of the blank levels of water and acid is very important. Generally ultrapure water and acid of high purity, e.g. cleaned by sub boil distillation, are recommended. Special facilities should be used in order to avoid contamination during the steps of prepara

26、tion and measurements (e.g. use of laminar flow benches or comparable clean room facilities). 4.2 Nitric acid Mass fraction not less than w(HNO3) = 65 %, with a density of approximately 1,4 g/ml. DIN EN 15763:2010-04 EN 15763:2009 (E) 5 4.3 Element stock solutions Commercially available single or mu

27、ltielemental standards with a mass concentration of = 1 000 mg/l of As, Au, Cd, Hg, Lu, Rh and Pb are recommended. Such standards are available in suitable concentrations from different suppliers. Stock solutions in diluted nitric acid are preferred. 4.4 Diluted mercury stock solution, (Hg) = 10 mg/

28、l Pipette 1 ml of Hg stock solution of (Hg) = 1 000 mg/l (4.3) and 1 ml of nitric acid (4.2) in a 100 ml volumetric flask and dilute with water to mark. 4.5 Diluted multi-element stock solution The concentration levels of the elements in the diluted multi-element stock solution may be chosen in the

29、relation to the type of samples analysed. EXAMPLE (As) = 20 mg/l, (Cd), (Pb) = 10 mg/l. Pipette 2 ml of As, 1 ml of Cd and Pb, respectively of each stock solution into a 100 ml volumetric flask , add 1 ml of nitric acid (4.2), dilute with water to the mark and transfer the solution into a suitable v

30、essel. 4.6 Multi-element calibration solution According to the example given under 4.5, the multi-element calibration solution contains: = 100 g/l As, = 50 g/l Cd, Hg, Pb. Pipette 0,5 ml diluted mercury stock solution (4.4) and 0,5 ml of the diluted multi-element stock solution (4.5) to a 100 ml vol

31、umetric flask, add 1 ml nitric acid (4.2), dilute with water to the mark and transfer the solution into a suitable vessel (PFA or quartz is recommended). 4.7 Internal standard solution The internal standard solution contains Rhodium and Lutetium with a mass concentration of = 1 000 mg/l. Gold is use

32、d to stabilise mercury in the solution and reduce memory effects. The internal standard/s should cover the mass range used for determination of the elements. Their concentrations in the test solutions should be negligible. 4.8 Diluted internal standard solution The concentration of the diluted inter

33、nal standard solution should be high enough to give sufficient signal intensity. For an internal standard solution of (Au, Rh, Lu) = 5 mg/l, pipette 0,5 ml of Au, Rh and Lu internal standard solution (4.7) each into a 100 ml flask, add 1 ml of nitric acid (4.2), dilute to volume with water and trans

34、fer the solution into a suitable vessel. 4.9 Optimising solution The optimising solution is used for check and optimising procedures during set up of the ICP-MS. It is used for mass calibration purposes and for adjustment of maximum sensitivity at low rates of oxides and doubly charged ions. The opt

35、imising solution should contain elements that cover the whole mass range giving a high rate of oxides and doubly charged ions. The solutions recommended by the manufacturer of the ICP-MS instrument may be used. A solution containing e.g. Y, Rh, Ce and Pb is suitable for those purposes. The concentra

36、tion of these elements should be chosen in order to achieve a count rate of 10 000 to 100 000. 4.10 Blank solution The blank solution contains water and the same amount of acid used in the calibration solution. DIN EN 15763:2010-04 EN 15763:2009 (E) 6 5 Apparatus and equipment 5.1 General Stability

37、of test and diluted stock solutions are greatly influenced by the material of which the storage vessel is made. For the determination of elements in trace or ultra trace concentrations vessels made of quartz or fluoropolymers (polytetrafluoroethylene PTFE, perfluoroalkoxy PFA) are highly recommended

38、 Glass or polyvinylchloride (PVC) should not be used. Vessels made of other materials may be used as long as they do not affect the results. The vessels should be carefully cleaned and rinsed. 5.2 Inductively Coupled Plasma Mass Spectrometer (ICP-MS) Mass spectrometer with inductively coupled argon

39、 plasma operating in a mass range from 5 amu to 240 amu. Using routine settings the mass spectrometer shall be capable to resolve 1 amu peak width at 5 % peak height or better (resolution 300) and have a sensitivity to achieve the detection limits listed in Table 2. Mass spectrometers with additiona

40、l reaction or collision cells may be used to reduce the influence of polyatomic ions. Sectorfield mass spectrometers that allow the separation of the polyatomic ions by the use of high resolution settings may also be used. The ICP-MS, having a nebulising system with a low pulsion peristalic pump, sh

41、ould be equipped with a mass flow controller for the nebuliser gas. 5.3 Argon Purity of at least 99,99 %. 6 Procedure 6.1 Sample pretreatment Food samples are treated by a pressure digestion method according to EN 13805. The digested solution is diluted by water to a known volume (test solution). Th

42、e concentration of nitric acid used in the calibration solutions should be similar to the final concentrations of nitric acid in the test solution. If hydrogen peroxide was added for the digestion, the calibration solutions need no addition of hydrogen peroxide. 6.2 ICP-MS 6.2.1 General The correlat

43、ion between the concentration of the element and the count rate measured is linear over some orders of magnitude. Therefore linear calibration functions can be used. The concentration range of the linearity should be checked regularly for each element. ICP-MS instruments with dual-detector capabilit

44、ies, having an extended linear range, additionally need a regular check of the cross calibration factor of the two detectors. DIN EN 15763:2010-04 EN 15763:2009 (E) 7 6.2.2 ICP-MS settings Table 1 Example of instrument settings for ICP-MS Parameter Setting RF-Power (W) 1 500 Carrier gas flow (l/min)

45、 1,2 Plasma gas flow (l/min) 15 Auxiliary gas flow (l/min) 1,0 Spray chamber Water cooled double pass Spray chamber temperature (C) 2 Lens voltage 4,5 Mass resolution 0,8 Integration time points/ms 3 Points per peak 3 Replicates 3 The instrument parameters described in the manufacturers operating ma

46、nual should be used. Generally, a plasma power of 1 100 W to 1 500 W should be chosen. By use of shorter or longer integration times on the isotope, the sensitivity may be influenced in some extend. Generally, three repeated measurements of each solution should be done. An example of instrument sett

47、ings is given in Table 1. 6.2.3 Set up procedures for the ICP-MS Before starting routine measurements the following set up procedure should be run: The ICP-MS should warm up in full running mode for a minimum 20 min to 30 min. Mass resolution, mass calibration, sensitivity and stability of the syste

48、m are checked by the use of a suitable optimising solution (4.9). With an optimising solution the ICP-MS is adjusted daily to achieve maximum ion signals and both low oxide rates (e.g. 2 %) and low rates of doubly charged ions (e.g. 2 %). If a collision or reaction cell instrument is used, the flow

49、rate of the cell gas(es) should be optimised, in order to ensure sufficient reduction of polyatomic interferences. If a high resolution mass spectrometer is used, mass calibration and sensitivity shall be checked for every range of resolution used. Check the sample feed and washout times with respect to the length of the tubing. If large differences in concentration of the test solutions are expected, the sample feed and washout times should be prolonged. 6.3 Interferences