《BS EN 1541-2001 Paper and board intended to come into contact with foodstuffs - Determination of formaldehyde in an aqueous extract.pdf》由会员分享，可在线阅读，更多相关《BS EN 1541-2001 Paper and board intended to come into contact with foodstuffs - Determination of formaldehyde in an aqueous extract.pdf（12页珍藏版）》请在三一文库上搜索。
1、BRITISH STANDARD BS EN 1541:2001 Paper and board intended to come into contact with foodstuffs Determination of formaldehyde in an aqueous extract The European Standard EN 1541:2001 has the status of a British Standard ICS 67.250; 85.060 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYR
2、IGHT LAW BS EN 1541:2001 This British Standard, having been prepared under the direction of the Consumer Products and Services Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 June 2001 BSI 06-2001 ISBN 0 580 37328 2 National foreword This Br
3、itish Standard is the official English language version of EN 1541:2001. It supersedes BS EN 1541:1998 which is withdrawn. The UK participation in its preparation was entrusted by Technical Committee CW/47, Materials in contact with food, to Subcommittee CW/47/3, Paper and board in contact with food
4、stuffs, which has the responsibility to: A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards
5、Catalogue under the section entitled “ International Standards Correspondence Index” , or by using the “ Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for
6、 their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests inform
7、ed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document 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 date displayed in this document indicate
8、s when the document was last issued. Amendments issued since publication Amd. No. DateComments EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 1541 April 2001 ICS 67.250; 85.060Supersedes EN 1541:1998 English version Paper and board intended to come into contact with foodstuffs - Determination
9、of formaldehyde in an aqueous extract Papiers et cartons destins entrer en contact avec les denres alimentaires - Dtermination du formaldhyde dans un extrait aqueux Papier und Pappe vorgesehen fr den Kontakt mit Lebensmitteln - Bestimmung von Formaldehyd in einem wssrigen Extrakt This European Stand
10、ard was approved by CEN on 19 February 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
11、 such national standards may be obtained 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 languag
12、e and notified to the Management Centre 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, Switz
13、erland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2001 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No.
14、 EN 1541:2001 E Page 2 EN 1541 : 2001 Contents Page Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15、. . . . . . . . . . .4 2Normative References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 3Terms and definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 4Principle . .
16、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 5Reagents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 6Apparatus . . . . . . . . . . . . .
17、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 7Preparation of sample . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 8Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 9Calculation and expression of results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 10Confirmation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19、. . . . . . . . . . . . . . .7 11Repeatability and reproducibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 12Test report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
20、 ? Page 3 EN 1541 : 2001 Foreword This European Standard 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 national standard, either by publication of an identical text or by end
21、orsement, at the latest by October 2001, and conflicting national standards shall be withdrawn at the latest by October 2001. This European Standard supersedes EN 1541:1998. With regard to EN 1541 : 1998-06 and EN 1541 : 1998/AC the following changes have been made: a) deletion of the Butan-1-ol ste
22、p; b) correction of the formula 2 by incorporation of EN 1541 : 1998/AC; c) addition of more precise information on the reproducibility, see 11.2; d) editorial updating. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to im
23、plement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ? Page 4 EN 1541 : 2001 1 Scope This European Standard specifies the det
24、ermination of formaldehyde in aqueous extracts prepared from paper and board intended to come into contact with foodstuffs. The limit of determination is 1 mg/kg. This means that for a paper with a grammage of 100 g/m the limit of determination will be 0,001 mg/dm. For contact at room temperature th
25、e cold water extract is applied. For paper and board materials intended for boiling and hot filtering purposes the hot water extract is applied. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references ar
26、e 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 references the latest e
27、dition of the publication referred to applies (including amendments). EN 645 Paper and board intended to come into contact with foodstuffs Preparation of a cold water extract EN 647 Paper and board intended to come into contact with foodstuffs Preparation of a hot water extract 3 Terms and definitio
28、ns For the purposes of this Standard the following terms and definitions apply: 3.1 cold water extract: the water solution obtained as a result of cold extraction EN 645. 3.2 hot water extract: the water solution obtained as a result of hot extraction EN 647. 4 Principle Formaldehyde reacts with pen
29、tane-2,4-dione (acetylacetone) in the presence of ammonium acetate to form 3,5-diacetyl-1,4-dihydrolutidine. The absorbance of the extract is measured at a wavelength of 410 nm. NOTE The extract should also be scanned by ultraviolet (UV) spectroscopy for confirmation where the level of formaldehyde
30、exceeds specified limits (see clause 10). 5 Reagents All reagents shall be of analytical grade and the water shall be distilled or of equivalent purity. 5.1 Anhydrous ammonium acetate 5.2 Acetic acid 99% (d = 1,05) 5.3 Pentane-2,4-dione 5.4 Hydrochloric acid, 1 mol/l 5.5 Sodium hydroxide solution, 1
31、 mol/l 5.6 Starch solution freshly prepared, 2 g/l 5.7 Formaldehyde solution, 370 g/l to 400 g/l 5.8 Standard iodine solution, 0,05 mol/l 5.9 Standard sodium thiosulphate solution, 0,1 mol/l 5.10 Pentane-2,4-dione reagent In a 100,0 ml volumetric flask dissolve: -15,0 g anhydrous ammonium acetate (s
32、ee 5.1); -0,2 ml pentane-2,4-dione (see 5.3); -0,3 ml acetic acid (see 5.2); -25 ml of water. Make up to 100,0 ml with water. This reagent shall be freshly prepared. 5.11 Reagent (see 5.10) without pentane-2,4-dione ? Page 5 EN 1541 : 2001 5.12 Formaldehyde-standard: Stock solution Measure 5,0 ml fo
33、rmaldehyde solution (see 5.7) into a 1000 ml volumetric flask and make up to 1000 ml with water. Just before use determine the concentration of this solution as follows. Transfer 10,0 ml of the stock solution into a conical flask, add 25,0 ml of a standard iodine solution (see 5.8) and 10,0 ml of so
34、dium hydroxide solution (see 5.5). Allow to stand for 5 min. Acidify with 11,0 ml of hydrochloric acid (see 5.4) and determine the excess iodine by titration with a standard sodium thiosulphate solution (see 5.9), using 0,1 ml of the starch solution (see 5.6) as indicator. NOTE Add the starch soluti
35、on when the solution being titrated has become a pale straw colour. Theoretically, 1,0 ml of 0,05 mol/l iodine consumed is equivalent to 1,5 mg formaldehyde. 5.13 Formaldehyde-standard: Dilute solution Dilute an aliquot of the formaldehyde stock solution (see 5.12) to 20 times its volume with water,
36、 and then further dilute an aliquot of this second solution to 100 times its volume so that 1,0 ml of the final solution contains about 0,001 mg of formaldehyde. Use pipettes and volumetric flasks. Calculate the actual formaldehyde content. This solution shall be freshly prepared. 6 Apparatus 6.1 Or
37、dinary laboratory apparatus 6.2 Spectrometer for use at the wavelength of 410 nm, with cells of an optical path length of 10 mm. 6.3 Scanning ultraviolet (UV) spectrometer in the range of 300 nm to 500 nm (Only for the confirmation steps). 6.4 Thermostatic water-bath capable of maintaining a tempera
38、ture of (60 2) C. 7 Preparation of sample Sampling, sample preparation and extraction shall be carried out according to the methods for the preparation of cold water (see EN 645) or hot water extracts (see EN 647). Two parallel extractions shall be carried out. The test shall be performed not longer
39、 than 24 h after extraction. ? Page 6 EN 1541 : 2001 8 Procedure 8.1 For each extract at least two parallel determinations shall be carried out. 8.2 Sample solution Into a 50 ml conical flask add - 25,0 ml extract (V1) (see 8.1); -5,0 ml pentane-2,4-dione reagent (see 5.10). 8.3 Reference solution P
40、ossible interference due to coloured substances in the aqueous extract is eliminated by the use of this reference solution. Into a 50 ml conical flask add - 25,0 ml extract (see 8.1); -5,0 ml reagent without pentane-2,4-dione (see 5.11). 8.4 Blank test This is performed in order to construct the cal
41、ibration curve. Into a 50 ml conical flask add - 25,0 ml water; -5,0 ml pentane-2,4-dione reagent (see 5.10). 8.5 Determination Shake the solutions 8.2, 8.3 and 8.4 for about 15 s. Immerse the conical flasks in a thermostatic waterbath (see 6.4) at (60 2) for 10 min 10 s. Allow to cool for at least
42、2 min in a bath of iced water. Bring the solutions into the measuring cells (see 6.2). Measure the absorbance at 410 nm of the sample solution (see 8.2) with the reference solution (see 8.3) in the reference cell (A1). Measure the absorbance of the blank test (see 8.4) with water in the reference ce
43、ll (A2). The absorbance measurements shall be made between 35 min and 60 min from the time when the conical flasks were placed in the water bath at 60 C. If the value of formaldehyde obtained exceeds the range covered by the calibration solutions, the measurement shall be repeated with a more dilute
44、 sample solution and using an equally diluted reference solution. 8.6 Calibration curve Into a 50 ml conical flask add: -1,0 ml of the formaldehyde diluted standard solution (see 5.13); -5,0 ml of the pentane-2,4-dione reagent (see 5.10); -make up with water to 30,0 ml. Continue as described in 8.5
45、and measure the absorbance with water (see 8.5) in the reference cell. Repeat the procedure with 5,0 ml; 10,0 ml; 15,0 ml; 20,0 ml and 25,0 ml of the formaldehyde diluted standard solution (see 5.13). Construct the calibration curve after subtraction of the blank test value (see 8.5) from each of th
46、e absorbances obtained. ? Page 7 EN 1541 : 2001 9 Calculation and expression of results 9.1 Subtract A2 from A1 and read off from the calibration curve (see 8.6) the amount C in mg of formaldehyde in the sample solution (see 8.2). 9.2 Calculate the formaldehyde content of the sample (Cs ) or (Cm ) a
47、s follows: (1) CsCx V0 V1 x b 100 x 1 G (2) CmCx V0 V1 x 1 G x 100 100f x 1000 where: Csamount of formaldehyde soluble of the sample in mg/dm; Cmamount of formaldehyde soluble of the sample in mg/kg; Camount of formaldehyde read from the calibration graph, in mg; V0total volume of extract (250 ml),
48、in ml; V1volume taken for the test (25,0 ml), in ml; bgrammage, in g/m Gmass, in grams, of the sample taken under the same condition as grammage; fmoisture content of the sample, in %. Report the result with two significant figures. 10 Confirmation 10.1 Requirement for confirmation Where the level o
49、f formaldehyde in the water extract under test (see clause 7) exceeds any specified limit, the determination shall be confirmed by scanning ultraviolet (UV) spectroscopy (see 6.3). 10.2 Standard spectrum Whilst preparing the formaldehyde derivative (see 8.5), scan the intermediate standard (10,0 ml standard from 8.6) from 300 nm to 500 nm. Record the position and absorbance value at the peak maximum and calculate the ratio of the measurements of the absorbance measured at 20 nm increments