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1、DRAFT FOR DEVELOPMENT DD ISO/TS 6733:2006 Milk and milk products Determination of lead content Graphite furnace atomic absorption spectrometric method ICS 67.100.01 ? Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Licensee=Boeing Co/5910770001, Use
2、r=Japan, IHS Not for Resale, 10/17/2008 22:54:32 MDTNo reproduction or networking permitted without license from IHS -,-,- DD ISO/TS 6733:2006 BSI 2008 ISBN 978 0 580 57807 6 National foreword This Draft for Development is the UK implementation of ISO/TS 6733:2006. This publication is not to be rega
3、rded as a British Standard. It is being issued in the Draft for Development series of publications and is of a provisional nature. It should be applied on this provisional basis, so that information and experience of its practical application can be obtained. Comments arising from the use of this Dr
4、aft for Development are requested so that UK experience can be reported to the international organization responsible for its conversion to an international standard. A review of this publication will be initiated not later than three years after its publication by the international organization so
5、that a decision can be taken on its status. Notification of the start of the review period will be made in an announcement in the appropriate issue of Update Standards. According to the replies received by the end of the review period, the responsible BSI Committee will decide whether to support the
6、 conversion into an international Standard, to extend the life of the Technical Specification or to withdraw it. Comments should be sent to the Secretary of the responsible BSI Technical Committee at British Standards House, 389 Chiswick High Road, London W4 4AL. The UK participation in its preparat
7、ion was entrusted to Technical Committee AW/5, Chemical analysis of milk and milk products. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsibl
8、e for its correct application. Amendments/corrigenda issued since publication DateComments This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2008 Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrol
9、led Copy Licensee=Boeing Co/5910770001, User=Japan, IHS Not for Resale, 10/17/2008 22:54:32 MDTNo reproduction or networking permitted without license from IHS -,-,- Reference numbers ISO/TS 6733:2006(E) IDF/RM 133:2006(E) TECHNICAL SPECIFICATION ISO/TS 6733 IDF/RM 133 First edition 2006-11-01 Milk
10、and milk products Determination of lead content Graphite furnace atomic absorption spectrometric method Lait et produits laitiers Dtermination de la teneur en plomb Mthode spectromtrique dabsorption atomique avec four de graphite DD ISO/TS 6733:2006 Copyright British Standards Institution Provided b
11、y IHS under license with BSI - Uncontrolled Copy Licensee=Boeing Co/5910770001, User=Japan, IHS Not for Resale, 10/17/2008 22:54:32 MDTNo reproduction or networking permitted without license from IHS -,-,- ii Copyright British Standards Institution Provided by IHS under license with BSI - Uncontroll
12、ed Copy Licensee=Boeing Co/5910770001, User=Japan, IHS Not for Resale, 10/17/2008 22:54:32 MDTNo reproduction or networking permitted without license from IHS -,-,- iii Contents Page Foreword iv Foreword. v Introduction. vi 1 Scope . 1 2 Normative references. 1 3 Terms and definitions. 1 4 Principle
13、. 1 5 Reagents 2 6 Apparatus 3 7 Sampling 3 8 Preparation of test sample. 4 9 Procedure 4 9.1 Dry ashing . 4 9.2 Mineralization in a closed vessel (bomb digestion) 5 9.3 Measurements. 5 10 Calculation and expression of results 7 10.1 Automated calculation . 7 10.2 Calculation using a calibration gra
14、ph. 7 10.3 Calculation using standard additions. 8 10.4 Expression of results . 8 11 Precision 9 11.1 Interlaboratory test. 9 11.2 Repeatability 9 11.3 Reproducibility 9 12 Test report . 9 Annex A (informative) Interlaboratory trials 10 Annex B (informative) Applicability of dry ashing as a minerali
15、zation procedure 12 Bibliography. 13 DD ISO/TS 6733:2006 Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Licensee=Boeing Co/5910770001, User=Japan, IHS Not for Resale, 10/17/2008 22:54:32 MDTNo reproduction or networking permitted without license fr
16、om IHS -,-,- iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subje
17、ct for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC
18、) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committe
19、es are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. In other circumstances, particularly when there is an urgent market requirement for such documents, a technical committee may decide to
20、publish other types of normative document: an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in an ISO working group and is accepted for publication if it is approved by more than 50 % of the members of the parent committee casting a vote; an ISO Tec
21、hnical Specification (ISO/TS) represents an agreement between the members of a technical committee and is accepted for publication if it is approved by 2/3 of the members of the committee casting a vote. An ISO/PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirm
22、ed for a further three years, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is confirmed, it is reviewed again after a further three years, at which time it must either be transformed into an International Standard or be withdrawn. Attention is drawn to the poss
23、ibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO/TS 6733IDF/RM 133 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products, and
24、the International Dairy Federation (IDF). It is being published jointly by ISO and IDF. DD ISO/TS 6733:2006 Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Licensee=Boeing Co/5910770001, User=Japan, IHS Not for Resale, 10/17/2008 22:54:32 MDTNo repr
25、oduction or networking permitted without license from IHS -,-,- v Foreword IDF (the International Dairy Federation) is a worldwide federation of the dairy sector with a National Committee in every member country. Every National Committee has the right to be represented on the IDF Standing Committees
26、 carrying out the technical work. IDF collaborates with ISO in the development of standard methods of analysis and sampling for milk and milk products. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the Action Teams and Standing
27、Committees are circulated to the National Committees for voting. Publication as an International Standard requires approval by at least 50 % of the IDF National Committees casting a vote. In other circumstances, particularly when there is an urgent market requirement for such documents, a Standing C
28、ommittee may decide to publish an other type of normative document which is called by IDF: Reviewed method. Such a method represents an agreement between the members of a Standing Committee and is accepted for publication if it is approved by at least 50 % of the committee members casting a vote. A
29、Reviewed method is equal to an ISO/PAS or ISO/TS and will, therefore, also be published jointly under ISO conditions. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. IDF shall not be held responsible for identifying any or all suc
30、h patent rights. ISO/TS 6733IDF/RM 133 was prepared by the International Dairy Federation (IDF) and Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products. It is being published jointly by IDF and ISO. All work was carried out by the Joint ISO-IDF Action Team on Mino
31、r compounds, of the Standing Committee on Minor components and characterization of physical properties, under the aegis of its project leader, Dr. G. Ellen (NL). This edition of ISO/TS 6733IDF/RM 133 cancels and replaces IDF 133A:1992, which has been technically revised. DD ISO/TS 6733:2006 Copyrigh
32、t British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Licensee=Boeing Co/5910770001, User=Japan, IHS Not for Resale, 10/17/2008 22:54:32 MDTNo reproduction or networking permitted without license from IHS -,-,- vi Introduction The method described in the first ed
33、ition of IDF 133A:1992 was not up-to-date, was based on another technique and also did not fulfil the requirements for a fully validated International Standard. A new interlaboratory test on the up-dated method as described in this Technical Specification (Reviewed Method) was organized in 2004 in a
34、ccordance with ISO 5725-1 and ISO 5725-2. However, the requirements for a reliable study were not fulfilled due to outliers, lack of participants and misinterpretations on the use of the method. To maintain the method because several laboratories are using it, experts decided to publish the method a
35、s an ISO Technical Specification and IDF Reviewed Method rather than an International Standard. DD ISO/TS 6733:2006 Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Licensee=Boeing Co/5910770001, User=Japan, IHS Not for Resale, 10/17/2008 22:54:32 MD
36、TNo reproduction or networking permitted without license from IHS -,-,- 1 Milk and milk products Determination of lead content Graphite furnace atomic absorption spectrometric method 1 Scope This Technical Specification describes a method for the quantitative determination of the total lead content
37、in milk and milk products. The detection limit of the method, defined as three times the standard deviation of the blank determination, is 0,001 mg/kg for liquid products and 0,01 mg/kg for solid products if dry ashing is applied. For pressurized wet mineralization, these figures are the same for te
38、st portions containing 0,2 g of dry matter. Microwave mineralization allows for larger test portions, and detection limits are accordingly lower. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition c
39、ited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 648, Laboratory glassware One-mark pipettes ISO 1042, Laboratory glassware One-mark volumetric flasks ISO 3696, Water for analytical laboratory use Specification and test metho
40、ds ISO 6732:1985, Milk and milk products Determination of the iron content Spectrometric method (Reference method)1) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 lead content mass fraction of substance determined by the procedure specified
41、 in this Technical Specification NOTE The lead content is expressed as milligrams per kilogram of sample. 4 Principle A test portion is mineralized by means of programmed dry ashing with sulfuric acid as the ashing aid. Alternatively, it is mineralized by pressurized wet mineralization with nitric a
42、cid in a teflon or quartz vessel, or by microwave wet mineralization. The ash is dissolved in dilute nitric acid, or the wet mineralisate is evaporated to dryness and the residue is dissolved in dilute nitric acid. The atomic absorption of the resulting 1) Equivalent to IDF 103A. DD ISO/TS 6733:2006
43、 Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Licensee=Boeing Co/5910770001, User=Japan, IHS Not for Resale, 10/17/2008 22:54:32 MDTNo reproduction or networking permitted without license from IHS -,-,- 2 solution is measured at a wavelength of 2
44、83,3 nm with a graphite furnace atomic absorption spectrometer with Zeeman or deuterium-arc background correction. Quantification is carried out by means of a calibration graph or by the method of standard additions. 5 Reagents Unless otherwise stated, all reagents and solvents shall be of analytica
45、l reagent (AR) grade. 5.1 Water, double-distilled or of similar purity, complying with the requirements of ISO 3696, grade 2. 5.2 Concentrated nitric acid (HNO3), 20(HNO3) = 1,40 g/ml, for cleaning purposes. 5.3 Concentrated nitric acid (HNO3), 20(HNO3) = 1,40 g/ml, Merck “Suprapur“ 2) or equivalent
46、. 5.4 Concentrated sulfuric acid (H2SO4), 20(H2SO4) = 1,84 g/ml, Merck “Suprapur“ 2) or equivalent. 5.5 Sulfuric acid solution, 20 % (mass/volume fraction). Dilute 130 ml of concentrated sulfuric acid (5.4) with water to 1 000 ml. 5.6 Matrix modifiers. 5.6.1 Dissolve 2,0 g of ammonium dihydrogen pho
47、sphate (NH4H2PO4) (Baker “Ultrex“) 2) and 0,17 g of magnesium nitrate Mg(NO3)26H2O (Merck “Suprapur“) in water. Dilute to 100 ml. Suitable solutions are also commercially available e.g. from Perkin-Elmer No. B019-0634 2) (1 % Mg solution) and No. N930-3445 (10 % NH4H2PO4 solution). 5.6.2 Mix 200 l o
48、f a solution containing 1 % Pd (as nitrate, e.g. Perkin-Elmer No. B019-0635) 2) and 20 l of a solution containing 1% Mg (as nitrate, e.g. Perkin-Elmer No. B019-0634) 2) with 1,67 ml of water and 2 drops of nitric acid (5.3) 5.7 Concentrated lead standard solution, c(Pb) = 100 mg/l. Dissolve 159,9 mg of lead nitrate Pb(NO3)2 in water in a 1 000 ml one-mark volumetric flask (