BS-EN-13628-2-2002.pdf
BRITISH STANDARD BS EN 13628-2:2002 Packaging Flexible packaging material Determination of residual solvents by static headspace gas chromatography Part 2: Industrial methods The European Standard EN 13628-2:2002 has the status of a British Standard ICS 55.040 ? BS EN 13628-2:2002 This British Standard, having been prepared under the direction of the Consumer Products and Services Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 21 October 2002 © BSI 21 October 2002 ISBN 0 580 40626 1 National foreword This British Standard is the official English language version of EN 13628-2:2002. The UK participation in its preparation was entrusted by Technical Committee PKW/5, Primary and transport packaging, to Subcommittee PKW/5/26, Packaging made from flexible materials, 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 Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue 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. aid enquirers to understand the text; present to the responsible international/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, an inside front cover, the EN title page, pages 2 to 12, an inside back cover 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. DateComments EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN 13628-2 October 2002 ICS 55.040 English version Packaging - Flexible packaging material - Determination of residual solvents by static headspace gas chromatography - Part 2: Industrial methods Emballage - Matériaux d'emballages souples - Détermination des solvants résiduels par chromatographie en phase gazeuse et espace de tête statique - Partie 2: Méthodes industrielles Verpackung - Flexible Packstoffe - Bestimmung der Restlösemittel durch statische Dampfraumanalyse mittels Gaschromatographie - Teil 2: Industrielle Verfahren This European Standard was approved by CEN on 26 August 2002. 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 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 language 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, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels © 2002 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 13628-2:2002 E EN 13628-2:2002 (E) 2 Contents page Foreword3 1Scope 4 2Normative references 4 3Principle4 4Reagents.5 5Apparatus .5 6Sampling.8 7Test specimens8 8Incubation of the test specimens.8 9Procedure .9 10Precision data.12 11Test report 12 EN 13628-2:2002 (E) 3 Foreword This document EN 13628-2:2002 has been prepared by Technical Committee CEN/TC 261 “Packaging“, the secretariat of which is held by AFNOR. 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 April 2003, and conflicting national standards shall be withdrawn at the latest by April 2003. This standard is part of a standard for determination of residual solvents by static headspace gas chromatography, which is published in two parts: - Part 1: Absolute methods - Part 2: Industrial methods This part of EN 13628 should be read in conjunction with EN 13628-1. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. EN 13628-2:2002 (E) 4 1 Scope This part of this European Standard specifies rapid methods as commonly used in quality control for monitoring the level of residual solvents used in the production of flexible packaging by static headspace chromatography. The procedures described in this part involve one single injection of the headspace which implies an incomplete extraction of the solvent. The values obtained may be lower than the absolute content which should be determined according to Part 1. Residues from thermal decomposition products are not within the scope of this standard. The method is applicable to flexible packaging materials that may consist of mono- or multilayer plastic films, paper or board, foil or combinations thereof. This method does not apply to residual solvents with amounts lower than 0,5 mg/m². 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative 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 references the latest edition of the publication referred to applies (including amendments). ISO 2859-1, Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection. ISO 2859-2, Sampling procedures for inspection by attributes - Part 2: Sampling plans indexed by limiting quality (LQ) for isolated lot inspection. ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results - Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method. 3 Principle Specimens of the flexible packaging material are placed in a hermetically closed vial and heated under closely controlled conditions of time and temperature to vaporize solvents into the headspace. The amount of solvent released into the headspace is determined by transferring an aliquot of the headspace into a gas chromatograph for analysis. The transfer may be performed: a) by specific semi-automatic or automatic systems which allow pressurization of the heated vials; b) manually or automatically by using a heated gastight syringe or a loop without pressurization of the heated vials. The relative amount of residual solvent is determined by single headspace extraction using external or internal standards. NOTEFor reproducibility the same incubation conditions should be used for each single analysis. During the analysis, there could be interferences from possible products of thermal decomposition. Additional peaks due to these products should not be considered for evaluation of residual solvents. EN 13628-2:2002 (E) 5 4 Reagents 4.1 General All reagents shall be of a recognized analytical reagent grade. NOTEGrades stated as being suitable for chromatography can be commercially available and are recommended for use as reference for standard calibration solutions. Appropiate safety precautions should be used when handling toxic and/or flammable solvents. 4.2 Reference solvents, for the preparation of standard calibration solutions. 4.3 Dilution solvent, with a retention time different from those of residual solvents in the sample. NOTESolvents such as hexane, cyclohexanaone, acid amides and glycerol triacetate (triacetin) are appropriate. 5 Apparatus 5.1 Glass vials, of capacity 6 ml, 8 ml, 20 ml, 50 ml or 100 ml depending upon the specific requirements of accessory equipment, for example, the headspace sampler, fitted with an inert septum seal and aluminium crimp tops. The septum seal shall neither absorb nor release volatile components, shall be gas tight during incubation and shall permit samples of the headspace gas to be withdrawn by syringe for subsequent analysis. NOTEElastomers lined with polytetrafluoroethylene (PTFE) are suitable materials for septum seals. 5.2 Crimping tool, for sealing the vials with the aluminium crimp tops. 5.3 Seal removing tool. 5.4 Analytical balance, capable of weighing to the nearest 0,1 mg. 5.5 Template, for cutting samples. The dimensions of this template shall be matched to the vial volume used. 5.6 Scalpel, or sharp knife. 5.7 Syringes (e.g. 1 µl, 10 µl) 5.8 Gas chromatograph, having a flame ionization detector or equivalent for the solvents to be determined. 5.9 Gas chromatographic column, either packed or capillary, that will give good resolution of the solvents to be determined from any other components that might be injected with the specimen of the headspace. Examples for suitable columns and operation conditions are: a) Packed column length: 3 m; internal diameter: 3,2 mm; column filling: 80/120 mesh graphitised carbon, deactivated with polyethyleneglycol; carrier gas: N2, 20 ml/min; injector temperature: 220 °C; temperature programme: 80 °C; raised to 160 °C at 6 °C/min; raised to 225 °C at 1,5 °C/min; held for 16 min EN 13628-2:2002 (E) 6 NOTE 1A corresponding chromatogram obtained for a mixture of solvents is shown in Figure 1. Key 14,23 methanol 26,67 ethanol 39,25 acetone 417, 06 ethyl acetate 519,1 butanol 623,34 trichloroethylene 728,4 isobutyl acetate 833,87 methyl isobutyl ketone 941,86 toluene 1064.06 xylene ARetention time (min) BPeak height Figure 1 Example of chromatogram obtained with a packed column or b) Capillary column: (fused silica): length : 30 m; internal diameter : 0,32 mm; stationary phase : Poly(dimethylsiloxane) film thickness 3µm; carrier gas : He 1,7ml/min; carrier gas split ratio : 1:20; injector temperature : 230 °C; detector (flame ionisation) temperature : 280 °C; EN 13628-2:2002 (E) 7 temperature programme: 50 °C held for 5 min; raised to 100 °C at 5 °C/min; raised to 250 °C at 10 °C/min. NOTE 2A corresponding chromatogram is shown in Figure 2. Key 1Methanol 2Ethanol 3Isopropanol 4Methyl ethyl ketone 5Ethyl acetate 6Isobutanol 7Isopropyl acetate 8n-propyl acetate 9Methyl isobutyl ketone 10Etoxypropanol 11Toluene 12n-butyl acetate 13Xylene 14Butyl cellosolve ARetention time (min) BPeak height Figure 2 Example of chromatogram obtained with a capillary column NOTEOther apparatus which is more specific to the alternative methods is identified under the relevant clauses. EN 13628-2:2002 (E) 8 6 Sampling Sampling shall be in accordance with internal quality control procedures. Sampling shall follow ISO 2859-1 and ISO 2859-2. Samples of packaging materials that are to be analyzed shall be handled and stored so as to prevent either loss of volatile solvents or contamination by absorption of volatile solvents that may be present in the surrounding atmosphere. Sampling and analysis shall be done in a place where the air is solvent-free to reduce the problem of contamination from the surroundings due to the low concentration of residual solvents in the samples. NOTEIf samples need to be stored they should be in tightly packed roll form if possible. Sheet samples may be prepared from the roll by cutting out a square window (several layers of sheets) with a knife. When in form of sheets they should be stacked tightly together to form a compact “block” and wrapped tightly in a barrier material, preferably aluminium foil with a thickness of 30 µm to 40 µm. For storage periods of more than one hour the wrapped samples should be stored at temperatures below 5 °C and in an atmosphere free of volatile contaminants. 7 Test specimens 7.1 Specimen area in relation to vial volume The specimen area to be cut out shall depend on the vial volume and the level of residual solvents to be determined in the material. Usually the ratio between the specimen area (in cm²) and the vial volume (in ml) shall be between three and five. The specimens shall be cut out using an appropriate template (5.5). NOTEAs an example, for a vial with a volume of 6 ml to 9 ml a specimen of 30 cm² (2 cm × 15 cm) can be used or proportional dimensions for other volumes. 7.2 Test specimens From a representative sample (see clause 6) cut a specimen using a template (5.5). Coil the specimen rapidly and immediately put it into the vial. Crimp the vial immediately to seal it. The following precautions shall be taken: - the different steps of the preparation shall be done very rapidly to avoid evaporation of the solvents; - the specimens shall always be cut at a defined place e.g. on the same drawing printed on the same place in the width and the template for cutting shall always be placed in the same manner. 8 Incubation of the test specimens Incubation temperature and time shall be chosen to suit the materials being tested and the solvents likely to be present. Conditions used shall be included in the test report. NOTEIncubation conditions of 110 °C for 20 min are recommended. In order to compare residual solvent levels, incubation conditions used shall be the same. To ensure repeatability, the temperature shall be accurate to ± 2 °C and time shall be accurate to ± 0,5 min. EN 13628-2:2002 (E) 9 9 Procedure 9.1 General Quantitative analysis of residual solvents shall be carried out using one of the two methods of static headspace chromatography described in this clause, as appropriate. The methods are: - semi-automatic or automatic injection (see 9.2); and - manual injection (see 9.3). 9.2 Semi-automatic or automatic injection 9.2.1 General This method shall be used where a semi-automatic or automatic headspace sampler is available which has an integrated system to heat the sample vials before automatic withdrawal and injecti
