《BS-EN-12498-2005.pdf》由会员分享，可在线阅读，更多相关《BS-EN-12498-2005.pdf（12页珍藏版）》请在三一文库上搜索。
1、BRITISH STANDARD BS EN 12498:2005 Paper and board Paper and board intended to come into contact with foodstuffs Determination of cadmium and lead in an aqueous extract The European Standard EN 12498:2005 has the status of a British Standard ICS 67.250; 85.060 ? BS EN 12498:2005 This British Standard
2、 was published under the authority of the Standards Policy and Strategy Committee on 13 December 2005 BSI 13 December 2005 ISBN 0 580 46955 7 National foreword This British Standard is the official English language version of EN 12498:2005. It supersedes DD ENV 12498:1998 which is withdrawn. The UK
3、participation in its preparation was entrusted by Technical Committee CW/47, Materials and articles in contact with foodstuffs, to Subcommittee CW/47/3, Paper and board in contact with foodstuffs, which has the responsibility to: aid enquirers to understand the text; present to the responsible inter
4、national/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its
5、secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic C
6、atalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This doc
7、ument comprises a front cover, an inside front cover, the EN title page, pages 2 to 8, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments EUROPEAN STANDARD N
8、ORME EUROPENNE EUROPISCHE NORM EN 12498 August 2005 ICS 67.250; 85.060Supersedes ENV 12498:1997 English Version Paper and board - Paper and board intended to come into contact with foodstuffs - Determination of cadmium and lead in an aqueous extract Papier et carton - Papiers et cartons destins entr
9、er en contact avec les denres alimentaires - Dtermination du cadmium et du plomb dans un extrait aqueux Papier und Pappe - Papier und Pappe fr den Kontakt mit Lebensmitteln - Bestimmung von Cadmium und Blei in einem wssrigen Extrakt This European Standard was approved by CEN on 27 June 2005. CEN mem
10、bers 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 obtained on applicat
11、ion to the Central Secretariat 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 Central Secretariat has the
12、same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia
13、, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2005 CENAll rights of exploitation in any form and by any means reserved worldwide fo
14、r CEN national Members. Ref. No. EN 12498:2005: E EN 12498:2005 (E) 2 Contents page Foreword 3 1 Scope.4 2 Normative references .4 3 Principle.4 4 Reagents4 4.1 General 4 4.2 Nitric acid (HNO3), 65 % (d = 1,42)4 4.2.1 Nitric acid (4.2), diluted 1 : 1 (V/V) with water.4 4.2.2 Nitric acid (4.2), dilut
15、ed to 1 % (V/V) with water4 4.3 Hydrochloric acid (HCl), 36 % (d = 1,19)4 4.4 Hydrochloric acid (HCl), 0,3 mol/l solution .4 4.5 Cadmium - stock solution (Cd) = 1000 mg/l5 4.6 Lead - stock solution (Pb) = 1000 mg/l5 4.7 Matrix modifiers 5 4.7.1 Ammonium dihydrogen phosphate (NH4H2PO4) solution, 100,
16、0 g/l 5 4.7.2 Palladium nitrate (Pd(NO3)2) solution, 21,7 g/l ( = 1 % Pd).5 4.7.3 Magnesium nitrate (Mg(NO3)2) solution, 61,0 g/l ( = 1 % Mg) .5 4.8 Gases for atomic absorption spectrometry5 5 Apparatus5 5.1 General 5 5.2 General laboratory equipment .5 5.3 Volumetric flasks, 1000 ml .5 5.4 Analytic
17、al balance, accuracy 0,1 mg.5 5.5 Micropipettes from 5,0 l to 20,0 l with plastique tips (high density polyethylene/polypropylene bottles).6 5.6 Atomic absorption spectrometer, with graphite tube furnace, and with background correction or inductively coupled plasma atomic emission spectrometer with
18、background correction and radio frequency-generator6 6 Preparation of sample 6 7 Procedure6 7.1 General 6 7.2 Preparation of reference solutions6 7.3 Determination of cadmium and lead6 7.3.1 General 6 7.3.2 Calibration curve.6 7.3.3 Suggested spectrometer settings6 7.3.4 Determination of blank value
19、.7 8 Expression of results7 9 Precision7 10 Test report.8 EN 12498:2005 (E) 3 Foreword This European Standard (EN 12498:2005) has been prepared by Technical Committee CEN/TC 172 “Pulp, paper and board”, the secretariat of which is held by DIN. This European Standard shall be given the status of a na
20、tional standard, either by publication of an identical text or by endorsement, at the latest by February 2006, and conflicting national standards shall be withdrawn at the latest by February 2006. This European Standard supersedes ENV 12498:1997. With regard to ENV 12498:1997, the following changes
21、have been made: a) introduction of the “Inductively coupled plasma emission spectroscopy (ICP)“; b) deletion of the chromium determination; c) addition of the clause “Precision“; d) editorial updating. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the fol
22、lowing countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Swed
23、en, Switzerland and United Kingdom. EN 12498:2005 (E) 4 1 Scope This European Standard is one in a series of Standards for the determination of heavy metals in an aqueous extract of paper or board intended for contact with food. This European Standard specifies the test method for the determination
24、of cadmium and lead in an aqueous extract. It is applicable to paper and paperboard with extractable metal contents exceeding 0,1 mg per kg for cadmium; 0,6 mg per kg for lead. NOTE 1 The above limits of determination are achieved by multiplying the actual limits existing today or proposed in Europe
25、 by 0,2. NOTE 2 Metal content levels below those given can be measured by this European Standard if very sensitive equipment is available and if all other laboratory conditions fulfil the requirements for trace element analysis. 2 Normative references The following referenced documents are indispens
26、able for the application of this European Standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 645, Paper and board intended to come into contact with foodstuffs Preparation of a c
27、old water extract EN 647, Paper and board intended to come into contact with foodstuffs Preparation of a hot water extract 3 Principle An aliquot portion from the stabilized cold water (see EN 645) or stabilized hot water extract (see EN 647) (see Clause 6) is analysed by atomic absorption spectrome
28、try (AAS) using a graphite tube furnace or inductively coupled plasma emission spectroscopy (ICP). 4 Reagents 4.1 General All reagents and the water used shall be suitable for trace element analysis. Store the solutions in high-density polyethylene/polypropylene bottles. 4.2 Nitric acid (HNO3), 65 %
29、 (d = 1,42) 4.2.1 Nitric acid (4.2), diluted 1 : 1 (V/V) with water 4.2.2 Nitric acid (4.2), diluted to 1 % (V/V) with water 4.3 Hydrochloric acid (HCl), 36 % (d = 1,19) 4.4 Hydrochloric acid (HCl), 0,3 mol/l solution EN 12498:2005 (E) 5 4.5 Cadmium - stock solution (Cd) = 1000 mg/l Dissolve 1,142 g
30、 of cadmium oxide (CdO) in the minimum volume of nitric acid (4.2.1). Make up to 1000 ml with diluted nitric acid (4.2.2). 4.6 Lead - stock solution (Pb) = 1000 mg/l Dissolve 1,598 g of lead nitrate (Pb(NO3)2) in the minimum volume of nitric acid (4.2.1). Make up to 1000 ml with diluted nitric acid
31、(4.2.2). 4.7 Matrix modifiers 4.7.1 Ammonium dihydrogen phosphate (NH4H2PO4) solution, 100,0 g/l 4.7.2 Palladium nitrate (Pd(NO3)2) solution, 21,7 g/l ( = 1 % Pd) 4.7.3 Magnesium nitrate (Mg(NO3)2) solution, 61,0 g/l ( = 1 % Mg) NOTE Commercially available standard solutions and matrix modifiers can
32、 be used if preferred. 4.8 Gases for atomic absorption spectrometry Nitrogen as appropriate Argon 5 Apparatus 5.1 General All flasks, pipettes etc. have to be washed with nitric acid before use and stored in dilute nitric acid (4.2.2) until required. Rinse with demineralized water before use. 5.2 Ge
33、neral laboratory equipment 5.3 Volumetric flasks, 1000 ml 5.4 Analytical balance, accuracy 0,1 mg EN 12498:2005 (E) 6 5.5 Micropipettes from 5,0 l to 20,0 l with plastique tips (high density polyethylene/polypropylene bottles) 5.6 Atomic absorption spectrometer, with graphite tube furnace, and with
34、background correction or inductively coupled plasma atomic emission spectrometer with background correction and radio frequency- generator 6 Preparation of sample Prepare a cold water or a hot water extract from the paper or board using the test methods described in EN 645 or EN 647 respectively. St
35、abilize the extract by addition of nitric acid (4.2) in the ratio of 1,0 ml per 100,0 ml of sample. Mix the aqueous extract well and take an aliquot portion for analysis. Use the appropriate matrix modifier(s) (4.7) according to the particular instrument in use and the analytical matrix of the extra
36、ct. 7 Procedure 7.1 General Detailed instructions depend on the form of the equipment used. Follow the instructions of the manufacturer of the equipment. Correct the background absorption by use of a suitable system. 7.2 Preparation of reference solutions Prepare the reference solutions daily by dil
37、uting the single element solutions with nitric acid (4.2.2). The concentration to be selected will depend on the instrument used and the expected concentrations in the extract. For lead, a reference solution containing 10,0 g/l is usually appropriate. For cadmium, a reference solution containing 1,0
38、 g/l is appropriate. Prepare a calibration blank using all the reagents except for the metal stock solutions. 7.3 Determination of cadmium and lead 7.3.1 General Carry out two parallel extractions. From each extract at least two parallel determinations shall be carried out. Determine the concentrati
39、on of the element by means of the calibration graph (7.3.2) or alternatively, by use of the method of standard addition. 7.3.2 Calibration curve The calibration curve shall contain at least 3 points and cover the total range of concentrations being measured. Calculate the concentration of the elemen
40、t from the measured absorption. 7.3.3 Suggested spectrometer settings Cadmium 228,8 nm Lead 217,0 nm or 283,3 nm (preferred) EN 12498:2005 (E) 7 7.3.4 Determination of blank value Submit the water and reagents used for the extraction to the test procedure to provide a blank value to be deducted from
41、 the extract value. NOTE Although not deprecated, the extract can only be supplied to the laboratory, together with the water used for the extraction. Without this, no blank can be determined and therefore not deducted from the extract value. If a partial blank is determined this should be reported.
42、 8 Expression of results Calculate the results with a computer or graphically. Take the blank value into consideration in the evaluation. Express the results in mg/kg or mg/dm of paper. Calculate the cadmium, lead content of the sample (Cm see formula (1), Cs see formula (2) as follows: 1000 1 100 1
43、001 0m = fG VCC (1) 100 1 1000 0 1000 s b G V C C= (2) where: Cm amount of cadmium or lead soluble of the sample in mg/kg; Cs amount of cadmium or lead soluble of the sample in mg/dm2; C concentration of cadmium or lead read from the calibration graph, in g/l; V0 total volume of extract, in ml; b gr
44、ammage, in g/m2; f moisture content of the sample, in %; G mass of the sample taken under the same condition as grammage, in g. NOTE 1 The extractable cadmium, lead content of the original paper or board may be calculated if data are available. NOTE 2 Trace element determinations are sensitive to a
45、number of sources of error. It is, therefore, recommended to check the performance of the system by running standard reference materials. Standard reference solutions are commercially available. Special attention should be paid to factors such as high blank levels caused by impure reagents or modifi
46、ers, contamination during handling of the solutions, adsorption on the walls of vessels, inadequate background correction or unmatched acid concentrations of sample and calibration solutions. The detection limit should be established by measuring a sufficient number of blanks to allow calculation of
47、 the standard deviation of the blank. The detection limit is determined as three times this standard deviation. 9 Precision From an interlaboratory test (n = 8) with two samples of a water extract with a known amount of added cadmium and lead the test method described above gave the overall standard
48、 deviation as shown in Table 1. EN 12498:2005 (E) 8 Table 1 Mean value Overall standard deviation (s) Reference value (added cadmium/lead) Sample Cd g/l Pb g/l Cd g/l Pb g/l Cd g/l Pb g/l 1 4,95 14,8 0,43 0,19 4,5 15 2 20,3 89,0 2,29 2,03 20 90 10 Test report The test report shall include the follow
49、ing information: a) reference to this European Standard; b) extraction method; c) type, origin and designation of sample; d) date of sampling; e) whether or not a blank value has been measured on the water used; f) date of receipt and date of analyses; g) test result; h) any departures from the specified procedure that may have affected the result. blank BS EN 12498:2005 BSI 389 Chiswick High Road London W4 4AL BSI Britis