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1、DRAFT FOR DEVELOPMENT DD CEN/TS 14577:2003 Materials and articles in contact with foodstuffs Plastics Polymeric additives Test method for the determination of the mass fraction of a polymeric additive that lies below 1 000 Daltons ICS 67.250, 83.040.30 ? DD CEN/TS 14577:2003 This Draft for Developme
2、nt was published under the authority of the Standards Policy and Strategy Committee on 16 January 2004 BSI 16 January 2004 ISBN 0 580 43260 2 National foreword This Draft for Development is the official English language version of CEN/TS 14577:2003. This publication is not to be regarded as a Britis
3、h Standard. It is being issued in the Draft for Development series of publications and is of a provisional nature because of the need to develop a reliable method of test for the determination of molecular weight fractions below 1 000 Daltons in polymeric additives. It should be applied on this prov
4、isional basis, so that information and experience of its practical application may be obtained. Comments arising from the use of this Draft for Development are requested so that UK experience can be reported to the European organization responsible for its conversion to a European standard. A review
5、 of this publication will be initiated 2 years after its publication by the European organization so that a decision can be taken on its status at the end of its 3-year life. Notification of the start of the review period will be made in an announcement in the appropriate issue of Update Standards.
6、According to the replies received by the end of the review period, the responsible BSI Committee will decide whether to support the conversion into a European standard, to extend the life of the Technical Specification or to withdraw it. Comments should be sent in writing to the Secretary of BSI Sub
7、committee CW/47/1, Migration from plastics, at British Standards House, 389 Chiswick High Road, London W4 4AL, giving the document reference and clause number and proposing, where possible, an appropriate revision of the text. A list of organizations represented on this committee can be obtained on
8、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 Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the B
9、SI Electronic Catalogue or of British Standards Online. Summary of pages This document comprises a front cover, an inside front cover, the CEN/TS title page, pages 2 to 14, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last
10、 issued. Amendments issued since publication Amd. No. DateComments TECHNICAL SPECIFICATION SPCIFICATION TECHNIQUE TECHNISCHE SPEZIFIKATION CEN/TS 14577 December 2003 ICS 67.250, 83.040.30 English version Materials and articles in contact with foodstuffs - Plastics - Polymeric additives - Test method
11、 for the determination of the mass fraction of a polymeric additive that lies below 1000 Daltons Werkstoffe und Gegenstnde in Kontakt mit Lebensmitteln Kunststoffe Polymere Zusatzstoffe Prfverfahren zur Bestimmung des Masseanteils eines polymeren Zusatzstoffes unter 1000 Dalton This Technical Specif
12、ication (CEN/TS) was approved by CEN on 17th March 2003 for provisional application. The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their comments, particularly on the question whether the CEN/TS can be conver
13、ted into a European Standard. CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS) until the final decision about the possible con
14、version of the CEN/TS into an EN is reached. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and Unit
15、ed Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2003 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN/TS 14577:2
16、003 CEN/TS 14577:2003 (E) 2 Contentspage Foreword3 1Scope 5 2Principle5 3Reagents.5 4Apparatus .6 5Preparation of standards and samples .8 6SEC analysis.8 7Expression of results 10 8Test report 11 Annex A (informative) Coupling of liquid chromatographic polymer separations with mass spectrometry 12
17、Annex ZA (informative) Clauses of this Technical Specification addressing essential requirements or other provisions of EU Directives13 Bibliography14 CEN/TS 14577:2003 (E) 3 Foreword This document (CEN/TS 14577:2003) has been prepared by Technical Committee CEN /TC 194, “Utensils in contact with fo
18、od“, the secretariat of which is held by BSI. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. For relationship with EU Directive(s), see informative annex ZA, which is an integral part of this document. Annex A is infor
19、mative. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to announce this European Specification: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Mal
20、ta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. CEN/TS 14577:2003 (E) 4 Introduction Some additives used to make plastics intended to come into contact with foodstuffs are known as polymeric additives 1. They are added to plastics in order to achieve a
21、 technical effect but they do not in isolation have the physical properties required of usable plastics materials and articles. In this respect they differ from the high polymers that are used to make plastics. These polymeric additives do not generally have a single molecular weight but they have a
22、 molecular weight distribution as a result of synthesis. They may also show further complexity with different end-group chemistry (because of different initiation and termination processes), different repeat units (because of two or more monomers used to make random or block copolymers) and differen
23、t chain shapes (because of the formation of linear, branched and cyclic structures within the chains). These additives may migrate into foodstuffs placed in contact with the plastics and so their safety must be evaluated. Only the fraction of the additive with molecular mass below 1000 Daltons (D) i
24、s regarded as being toxicologically relevant and so a distinction has been made by the Scientific Committee for Food (SCF) between polymeric additives with a weight averaged molecular mass (MW) below 1000 D and those with MW above 1000 D 2. For those polymeric additives with a MW above 1000 D, only
25、a reduced set of data may be required to allow an evaluation of their safety. The requirements of the SCF and the practical implications have been described and discussed in a Commission document 3. In deciding which toxicological information is needed, the SCF considers the data available on the mo
26、nomers used to make the polymeric additive, the size of the additive fraction with MW below 1000 D, and the formulation level of the additive used in the plastic 2. It is possible that a polymeric additive considered by the SCF is given approval to be used in plastics intended for food contact, but
27、with specifications including a limit on the mass fraction of the additive below MW 1000. For these reasons, for petitions and for testing for compliance, a method of test is required to determine the mass fraction of a polymeric additive that falls below the MW 1000 cut- off set by the SCF. CEN/TS
28、14577:2003 (E) 5 1 Scope This Technical Specification specifies a test method to determine the mass fraction of a polymeric additive that falls below a MW of 1000. The method is applicable to polymeric additives per se - i.e. supplied in their usable form, before formulation into a plastic. The meth
29、od is also applicable to polymeric additives extracted from finished plastic materials and articles, provided that precautions are taken to ensure the absence of any interference from any other co-extractives derived from the plastic. 2 Principle The polymeric additive is fractionated using size exc
30、lusion chromatography (SEC) and the mass fraction below MW 1000 D is determined either gravimetrically, off-line, or by using chromatographic detectors such as refractive index, infra-red, ultra-violet, or light-scattering detectors, on-line. The chromatogram is calibrated for molecular weight eithe
31、r by using calibration standards, where these substances are available, or by using mass-selective detectors such as mass spectroscopy. Under ideal conditions where there is no interaction with the stationary phase, in the SEC separation of oligo- or polymeric multicomponent systems the components a
32、re separated with respect to their hydrodynamic volumes. Consequently, retention times (elution volumes) indicate the molecular size and can be converted into molecular weight by use of calibration standards run concurrently or by using molecular weight sensitive detectors (on-line or off-line). The
33、 polymeric additive submitted to the test should be the same as that used to formulate the finished plastic material or article. If the additive is not available as such, then it may be extracted from the finished plastic and then submitted to this test procedure provided that care is taken to ensur
34、e that no significant interference occurs from any other co-extractives from the plastic. NOTEFor the separation of polar substances in aqueous systems, SEC is sometimes referred to as gel filtration chromatography (GFC). For the separation of organic substances in non-aqueous systems it is sometime
35、s called gel permeation chromatography (GPC). The term and abbreviation SEC is used here to describe all these types of chromatography. 3 Reagents 3.1 General All reagents shall be of recognised analytical quality, unless otherwise specified. 3.2 Molecular weight standards 3.2.1 General A variety of
36、 molecular weight standards are available commercially. Some are available in pure form, and others as mixtures with two or more species present. Since the aim of MW calibration is to set the 1000 D cut-off point in the SEC chromatogram, it is preferably to have one MW standard close to 1000 D with
37、two others each side (i.e. above and below 1000 D) so that the cut-off point can be determined by interpolation. 3.2.2 For polar polymeric additives Examples of polar polymeric additives include polyethylene glycols (PEGs), lignosulfonates, polyacrylamides and polyacrylates. PEG oligomers are common
38、ly used for SEC calibration in both aqueous and polar organic solvents. PEG calibrants are available commercially from the dimer (MW 106) upwards. Polyethylene oxide (PEO) standards are also available commercially. CEN/TS 14577:2003 (E) 6 3.2.3 For non-polar polymeric additives Examples of non-polar
39、 polymeric additives are hydrocarbon oils and waxes, hydrogenated hydrocarbon resins, and polyester plasticisers. Polystyrene oligomers and individual n-alkanes are the most widely used standards for calibrating SEC in organic solvents. Polystyrene oligomers are available commercially from the dimer
40、 (MW 162) upwards. A very large number of n-alkanes are available in pure form. 4 Apparatus 4.1 General An instrument or piece of apparatus is mentioned only if it is special, or made to particular specifications. Usual laboratory equipment is assumed to be available. 4.2 SEC equipment High performa
41、nce liquid chromatograph, equipped with a detector suitable for the polymeric additive under test, and fitted with a fraction collector if it is intended to collect fractions. The liquid chromatograph should be capable of maintaining a constant flow rate of mobile phase. NOTEUnder conditions of cons
42、tant flow, the retention time of a component is related directly to its elution volume which, on the particular SEC column employed, is a characteristic of its molecular size. 4.3 SEC column The column has to permit the separation of the polymeric additive according to its molecular weight distribut
43、ion. The column should be capable of separating the additive especially at the MW 1000 boundary and the pore size should be selected to give optimum separation in this region. NOTE 1The choice of the appropriate column type (stationary phase) depends on the molecular size and the chemical properties
44、 of the polymeric additives to be characterised. Most SEC columns will fractionate within a particular molecular weight range, determined by the pore size of the stationary phase. Large molecules are totally excluded from the stationary phase and are eluted with the void volume. Small molecules belo
45、w the fractionation range are eluted at an elution volume approximately equal to the total bed volume. A column should be chosen so that the critical cut-off point for this test - 1000 D - occurs not later than mid-way through the separation window between the totally excluded volume and the totally
46、 included volume. NOTE 2For on-line detection, the column should be an analytical column, with typical internal diameter of 3 to 7 mm. The column length required depends on the efficiency of the packing material employed. A typical column length would be 100 to 300 mm. Columns can be linked in serie
47、s if needed to increase the separation. NOTE 3For off-line detection, it is desirable to use a wider column bore to increase the sample capacity and so increase the mass of fraction collected for subsequent analysis off-line. The column should be a preparative or semi-preparative column, with typica
48、l internal diameter of 7 to 20 mm. The column length required depends on the efficiency of the packing material employed. A typical column length would be 200 to 300 mm. Columns can be linked in series if needed to increase the separation. NOTE 4The following combinations of column and mobile phase
49、(Table 1) have been found to be suitable for the types of polymeric additives indicated. CEN/TS 14577:2003 (E) 7 Table 1 SEC phases and calibrants found to be suitable for some typical polymeric additives Chemical characteristic of the polymeric additive SEC stationary phase(s) found to be suitable SEC mobile phase(s) found to be suitable Molecular weight standards found to be suitable for calibration purposes Non-polar additives Aliphatic hydrocarbon (e.g. waxes, polyolefins) Porous polyst
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