1、BRITISH STANDARD BS EN 1122:2001 Plastics Determination of cadmium Wet decomposition method The European Standard EN 1122:2001 has the status of a British Standard ICS 83.080.01 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS EN 1122:2001 This British Standard, having been p
2、repared under the direction of the Sector Committee for Materials and Chemicals, was published under the authority of the Standards Committee and comes into effect on 15 May 2001 BSI 05-2001 ISBN 0 580 37236 7 National foreword This British Standard is the official English language version of EN 112
3、2:2001. It supersedes DD ENV 1122:1995 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee PRI/21, Plastics test methods, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. C
4、ross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electr
5、onic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understa
6、nd the text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover,
7、an inside front cover, the EN title page, pages 2 to 7 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 1122 March 2001 ICS 8
8、3.080.01 Supersedes ENV 1122:1995 English version Plastics Determination of cadmium Wet decomposition method Plastiques Dtermination du cadmium Mthode par dcomposition par voie humide Kunststoffe Bestimmung von Cadmium Nassaufschlussverfahren This European Standard was approved by CEN on 18 January
9、2001. 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 concerning such national standards may be obtaine
10、d on application to the 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 language and notified to the Management Centre
11、 has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COM
12、MITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2001 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1122:2001 EPage 2 EN 1122:2001 BSI
13、 05-2001 Foreword This European Standard has been prepared by Technical Committee CEN/TC 249, Plastics, the Secretariat of which is held by IBN. 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 Sep
14、tember 2001, and conflicting national standards shall be withdrawn at the latest by September 2001. This European Standard replaces ENV 1122:1995. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European S
15、tandard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.Page 3 EN 1122:2001 BSI 05-2001 1 Scope This European Standard describes a method for the determ
16、ination of the total Cadmium (Cd) content in plastics in the range of 10 mg Cd/kg to 3 000 mg Cd/kg. It is not suitable for polyfluorinated plastic materials. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative
17、 references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated reference
18、s the latest edition of the publication referred to applies (including amendments). ISO 3696:1987 Water for analytical laboratory use Specification and test methods. ISO 3856-4:1984 Paints and varnishes Determination of “soluble” metal content Part 4: Determination of cadmium content Flame atomic ab
19、sorption spectrometric method and polarographic method. 3 Principle Wet decomposition of organic compounds and dissolution of cadmium compounds in a sample. Atomization of a solution in the flame of an atomic absorption spectrophotometer and the measurement of the absorbance at a wavelength of 228,8
20、 nm. 4 Reagents During the analysis, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity (ISO 3696:1987). 4.1 Sulfuric acid d = 1,83 g/l 95 % (m/m). 4.2 Nitric acid d = 1,40 g/l 65 % (m/m). 4.3 Hydrogen peroxide d = 1,10 g/l 30 % (m/m). 4.4 Cadmium
21、 metal with a purity of 99,9 % or a commercial cadmium standard stock solution (1 g Cd/l) (ISO 3856-4:1984). 4.5 Cadmium standard solutions (0,5 mg Cd/l and 1,0 mg Cd/l) (ISO 3856-4:1984). 5A p p a r a t u s 5.1 Apparatus for wet decomposition (e.g. Figure 1), Kjeldahl flask or any other suitable ap
22、paratus for wet decomposition. 5.2 Hot plate 5.3 Fume cupboard, preferably with air washing. 5.4 Flame atomic absorption spectrophotometer with background correction, e.g. D2 or Zeemann (ISO 3856-4:1984). 5.5 Hollow cathode lamp or EDL for cadmium (ISO 3856-4:1984). 5.6 Analytical balance with range
23、 of 1 mg. 5.7 Membrane filter with a pore size of 0,45 m.Page 4 EN 1122:2001 BSI 05-2001 6 Test procedure 6.1 Test sample Use homogeneous samples of at least 2 g for the analysis. Cut the sample into smaller pieces with a knife or scissors preferably in pieces less than 0,1 g. 6.2 Test portion Weigh
24、 approximately 0,5 g of the test samples (6.1) to the nearest mg into a decomposition apparatus, e.g. a Kjeldahl flask (5.1). Carry out the analysis in duplicate. 6.3 Wet decomposition The necessary time and reagent consumption for the decomposition depends on the particle size of the sample and mai
25、nly on the plastic materials. 6.3.1 Method A Wet decomposition by a mixture of sulfuric acid, nitric acid and hydrogen peroxide. The following method describes the decomposition in the decomposition apparatus (Figure 1), but any other suitable apparatus can be used (5.1). Carry out the decomposition
26、 in a fume cupboard (5.3). To flask B of the decomposition apparatus (Figure 1), add 10 ml of sulfuric acid (4.1). Connect the flask to the condensate reservoir, run water into the condenser, close taps R 1 and R 2 and add 10 ml of nitric acid (4.2) into the funnel. Using tap R 1, allow 1 ml to 2 ml
27、 of the nitric acid to run, then moderately heat until the material changes into a black mass and white fumes of SO 3are liberated. Now stop heating and allow 1 ml to 2 ml of the nitric acid to fall in drops. Reheat until white fumes appear. Repeat this procedure until a light yellow coloured soluti
28、on is obtained. After the addition of the last portion of nitric acid, open tap R 2 and allow the condensate to run into the flask, first dropwise in order to prevent a too violent reaction, then more rapidly. Close tap R 2, reheat until white fumes are produced. Allow to cool for some minutes and a
29、dd about 5 ml of hydrogen peroxide (4.3) into the flask using the funnel. Complete the decomposition by reheating for about 5 minutes. Stop heating, open tap R 2 and allow the condensate to drop slowly into the flask. After cooling to room temperature, rinse the apparatus with water and decant quant
30、itatively into a 100 ml one-mark volumetric flask. Dilute to the mark by adding distilled water and mix well. If insoluble matter exists at this stage which might disturb the atomic absorption method, then remove it by filtration, using a dry membrane filter (5.7). Prepare a reagent blank solution i
31、n the same way without using a test sample.Page 5 EN 1122:2001 BSI 05-2001 Key 1 towards hood 2 condenser to coil 3 condensate reservoir 4 R2: tap with PTFE fitting 5 25 ml funnel 6 B29 fitting 7 B14 fitting 8 250 ml flask 9 tripod 10 hot plate Figure 1 Example of apparatus for wet decompositionPage
32、 6 EN 1122:2001 BSI 05-2001 6.3.2 Method B Wet decomposition by a mixture of sulfuric acid and hydrogen peroxide. The following method describes the decomposition in a Kjeldahl flask but any other suitable apparatus can be used (5.1). Carry out the decomposition in a fume cupboard (5.3). Place the f
33、lask and its contents on the hot plate (5.2), add 10 ml of the sulfuric acid (4.1) and heat at a higher temperature to decompose and carbonize the organic substances. When white fumes are evolved continue heating for about 15 minutes. Take the flask from the hot plate and allow to cool for about 10
34、minutes. Add slowly, from the funnel, four 5 ml portions of hydrogen peroxide solution (4.3), allowing the reaction to subside after each addition. Note Because of the danger of splattering, any reaction flask should be kept covered between additions of hydrogen peroxide solution. Heat again for abo
35、ut 10 minutes and allow to cool for about 5 minutes. Add further 5 ml portions of the hydrogen peroxide solution and heat again. Stop this procedure only when no more organic matter remains. Allow to cool to room temperature and dilute cautiously with water. Rinse the flask with water and decant qua
36、ntitatively into a 100 ml one-mark volumetric flask. Dilute to the mark by adding distilled water and mix well. If insoluble matter exists at this stage which might disturb the atomic absorption method, then remove it by filtration, using a dry membrane filter (5.7). Prepare a reagent blank solution
37、 in the same way without using a test sample. 6.4 Determination Determine the cadmium concentration of the test solutions and the reagent blank solution obtained according to 6.3, by the method described in clause 3 of ISO 3856-4:1984. Note The sulfuric acid in the test and reagent blank solution mi
38、ght influence the results of the flame atomic absorption method; therefore use a background correction (5.4). For the determination of the cadmium concentration of the test solutions and the blank solutions other suitable techniques can be used, e.g. inductively-coupled plasma (ICP) or an isotope sp
39、ecific method. The used technique shall be noted in the test report. 7 Expression of results The total cadmium content of the sample is given by the following formula in mg/kg: M R C f ) ( 100 where: C is the cadmium concentration in milligrams per litre of the test solution obtained by 6.4; B is th
40、e cadmium concentration in milligrams per litre of the reagent blank solution obtained by 6.4; M is the mass, in grams of the test portion; f is the dilution factor of the test solution and the reagent blank solution used by clause 4. If the two results dont differ more than 20 % based on the averag
41、e (results between 10 mg Cd/kg and 50 mg Cd/kg) or 10 % (results between 50 mg Cd/kg and 3 000 mg Cd/kg), then take the mean. Otherwise repeat the analysis.Page 7 EN 1122:2001 BSI 05-2001 8 Precision Data of the Test Method Repeatability, r: The relative standard deviation between results, found on
42、identical test material, by one operator, using the same apparatus, using the method specified in this standard. Reproducibility, R: The relative standard deviation between independent results, found by two operators working in different laboratories, on identical test material, using the method spe
43、cified in this standard. Range of level r* R* 10 mg Cd/kg to 50 mg Cd/kg 50 mg Cd/kg to 3 000 mg Cd/kg 20% 10% 25% 25% % 100 m r r* % 100 m R R* where: m is the average of all values for each level. The precision data were determined from an experiment conducted in 1992 involving 7 laboratories, 6 s
44、amples and 5 different plastics (PE, PP, PS, PVC and PET). The precision data only refer to the 5 tested plastics. There exists a lot of experience that these data also can be used for the determination of the cadmium content of other sorts of plastics materials with the exemption of the polyfluorat
45、ed plastics. 9 Test Report The test reports shall contain at least the following information: a) type and identification of the products tested; b) a reference to this European Standard and a reference to the used method (A or B); c) the results of the test expressed as mg Cadmium/kg plastic materia
46、l (mean values and single measurement results); d) any deviation, by agreement or otherwise, from the test procedure specified here; e) date of the test and name of the operator.BS EN 1122:2001 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national
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