BS EN 15763-2009 Foodstuffs - Determination of trace elements - Determination of arsenic cadmium mercury and lead in foodstuffs by inductively coupled plasma mass spectrometry (ICP.pdf

1、BS EN 15763:2009ICS 67.050NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDFoodstuffs Determination oftrace elements Determination ofarsenic, cadmium,mercury and leadin foodstuffs byinductively coupledplasma massspectrometry (ICP-MS) after pressuredigestionLicens

2、ed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 02/04/2010 07:17, Uncontrolled Copy, (c) BSIThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 31 January2010 BSI 2010ISBN 978 0 580 61085 1Amendments/corrigenda issued since publicationDate CommentsB

3、S EN 15763:2009National forewordThis British Standard is the UK implementation of EN 15763:2009.The UK participation in its preparation was entrusted to TechnicalCommittee AW/-/3, Food analysis - Horizontal methods.A list of organizations represented on this committee can be obtained onrequest to it

4、s secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 02/04/2010 07:1

5、7, Uncontrolled Copy, (c) BSIBS EN 15763:2009EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15763 December 2009 ICS 67.050 English Version Foodstuffs - Determination of trace elements - Determination of arsenic, cadmium, mercury and lead in foodstuffs by inductively coupled plasma mass spectro

6、metry (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 induit par haute frquence et spectromtre de masse (ICP-MS) aprs digestion sous pression Lebensmittel - Bestimmung vo

7、n Elementspuren - Bestimmung von Arsen, Cadmium, Quecksilber und Blei in Lebensmitteln mit induktiv gekoppelter Plasma-Massenspektrometrie (ICP-MS) nach Druckaufschluss This European Standard was approved by CEN on 7 November 2009. CEN members are bound to comply with the CEN/CENELEC Internal Regula

8、tions 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 concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member. This E

9、uropean 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 language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the

10、 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

11、 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 All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 157

12、63:2009: ELicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 02/04/2010 07:17, Uncontrolled Copy, (c) BSIBS EN 15763:2009EN 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

13、quality control . 119 Limit of quantification 1110 Precision 1111 Test report . 13Annex A (informative) Results of the collaborative test . 14Bibliography . 18Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 02/04/2010 07:17, Uncontrolled Copy, (c) BSIBS EN 15763:2009EN 15763:2009 (E) 3 Forewo

14、rd This document (EN 15763:2009) 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, a

15、t the latest by June 2010, and conflicting national standards shall be withdrawn at the latest 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 a

16、ll 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, Ic

17、eland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 02/04/2010 07:17, Uncontrolled Copy, (c) BSIBS EN 15763:2009EN 15

18、763:2009 (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 (ICP-MS). The collaborative study included foodstuffs such as carrots, fish homogenate, Mushrooms (CRM), graham f

19、lour, 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 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.

20、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 references, the latest edition of the referenced document (including any amendments) applies. EN 13805, Foodstuffs De

21、termination 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 coupled argon plasma. The high temperature of the plasma is used to dry the aerosol and to atomise and ionise the e

22、lements. 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 determined by a pulse-count and/or analogue detector. WARNING The use of this method may involve hazardous material

23、s, 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 appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 4 Rea

24、gents 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 high sensitivity like ICP-MS, the control of the blank levels of water and acid is very important. Generally u

25、ltrapure 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 preparation and measurements (e.g. use of laminar flow benches or comparable clean room facilities). 4.2 Nitric acid M

26、ass fraction not less than w(HNO3) = 65 %, with a density of approximately 1,4 g/ml. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 02/04/2010 07:17, Uncontrolled Copy, (c) BSIBS EN 15763:2009EN 15763:2009 (E) 5 4.3 Element stock solutions Commercially available single or multielemental stan

27、dards 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/l Pipette 1 ml of

28、 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 relation to the t

29、ype 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 vessel. 4.6 Multi-

30、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 volumetric flask, ad

31、d 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 used to stabilise me

32、rcury 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 internal standard solu

33、tion 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 transfer the solution

34、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 optimising solution

35、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 concentration of these ele

36、ments 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. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 02/04/2010 07:17, Uncontrolled Copy, (c) BSIBS EN 1

37、5763:2009EN 15763:2009 (E) 6 5 Apparatus and equipment 5.1 General Stability 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 fluoropolyme

38、rs (polytetrafluoroethylene PTFE, perfluoroalkoxy PFA) are highly recommended. 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 Plasm

39、a Mass Spectrometer (ICP-MS) Mass spectrometer with inductively coupled argon 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 achi

40、eve the detection limits listed in Table 2. Mass spectrometers with additional 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.

41、The ICP-MS, having a nebulising system with a low pulsion peristalic pump, should 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. Th

42、e digested solution is diluted by water to a known volume (test solution). The 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

43、 need no addition of hydrogen peroxide. 6.2 ICP-MS 6.2.1 General The correlation 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 checke

44、d regularly for each element. ICP-MS instruments with dual-detector capabilities, having an extended linear range, additionally need a regular check of the cross calibration factor of the two detectors. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 02/04/2010 07:17, Uncontrolled Copy, (c) B

45、SIBS EN 15763:2009EN 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) 1,2 Plasma gas flow (l/min) 15 Auxiliary gas flow (l/min) 1,0 Spray chamber Water cooled double pass Spray chamber temperature (

46、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 manual 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 ti

47、mes 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 settings is given in Table 1. 6.2.3 Set up procedures for the ICP-MS Before starting routine measurements the following set up proced

48、ure 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 system are checked by the use of a suitable optimising solution (4.9). With an optimising solution the ICP-MS is adjusted daily to ach

49、ieve 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 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 tu