Document oe1zd7qBKbKa5LXvndeNyQbXo

TNO Triskelion TNO Triskelion Report V20318 Residual content of F-Diox Acid Ammonium Salt and its thermal decomposition products in a PTFE film Utrechtseweg 48 P.O. Box 844 3700 AV Zeist The Netherlands www.triskelion.nll T +31 88 866 28 00 F +31 88 866 69 70 Date 12 April 2013 Authors T.G. Siere, B. Sc., Wolfis G. B. Sc. Sponsor Solvay Specialty Polymers Italy S.p.A. TNO Triskelion project number TNO Triskelion study code Sponsor's study code 093.20444/01 - Status Previous versions Final - Number of pages 44 Number of tables 2 Number of figures 19 Number of annexes 3 Number of appendices - All rights reserved. No part of this publication may be reproduced and/or published by print, photoprint, microfilm or any other means without the previous written consent of TNO Triskelion. In case this report was drafted on instruction, the rights and obligations of contracting parties are subject to either the General Terms and Conditions for commissions to TNO Triskelion BV, or the relevant agreement concluded between the contracting parties. Submitting the report for inspection to parties who have a direct interest is permitted. Should any doubt arise from the publication of the TNO Triskelion report in an electronic form, the authorised printed version shall be considered authentic. 2013 TNO Triskelion BV TNO Triskelion Report | V20318 Annex 2 | 12 April 2013 Abbreviations EU EFSA FIA - ESI GC-MS LC-MS UPLC MRM PTFE European Union European Food Safety Authority Flow Injection Analysis with electro spray ionization mass detection Gas Chromatography with Mass detection Liquid Chromatography with Mass detection Ultra Performance Liquid Chromatography Multi Reaction Monitoring Polytetrafluoroethylene 1 / 20 TNO Triskelion Report | V20318 Annex 3 | 1 / 6 12 April 2013 Annex 3 Determination of the residual content of F-Diox Acid Ammonium Salt in a PTFE film Contents 1 Introduction 2 Scope 3 Principle 4 Reagents 5 Apparatus 6 Samples 7 Procedure 8 Precision 9 Test report 1 Introduction Acetic acid, 2,2-difluoro-2-[[2,2,4,5-tetrafluoro-5-(trifluoromethoxy)-1,3-dioxolan-4yl]oxy]-,ammonium salt (1:1) or F-Diox Acid Ammonium Salt (CAS Nr 1190931-27-1) is intended to be used as an emulsifier/dispersing agent in the polymerisation process of fluorinated polymers (PTFE). After manufacture, residual F-Diox Acid Ammonium Salt may remain in the final food contact material, and subsequently migrate into foodstuffs. The analytical method described below, allows for the determination of the residual content of F-Diox Acid Ammonium Salt in a PTFE film. 2 Scope This method describes an analytical procedure for the determination of the residual content of F-Diox Acid Ammonium Salt in a PTFE film in an approximate analyte concentration of 4 - 400 ng/ml. The final range expressed in mg per 6 dm or mg/kg polymer will depend on the concentration step, if any, applied prior to analysis for the level of F-Diox Acid Ammonium Salt and on the surface/weight ratio of the polymer investigated in the study. 3 Principle The sample is extracted with an appropriate solvent by refluxing for 4 hours. After the extraction period, the level of F-Diox Acid Ammonium Salt extracted from the sample is determined using liquid chromatography with mass detection (LC-MS). Quantification is performed by means of an external standard calibration. 4 Reagents NOTE: Reagents shall be of analytical quality. TNO Triskelion Report | V20318 Annex 3 | 2 / 6 12 April 2013 4.1 Analyte 4.1.1. Chemical name: Acetic acid, 2,2-difluoro-2-[[2,2,4,5-tetrafluoro-5(trifluoromethoxy)-1,3-dioxolan-4-yl]oxy]-,ammonium salt (1:1) - 41.9% solution in water Synonym: Trade name: CAS number: Molecular weight: Molecular formulae: Structure: F-Diox Acid Ammonium Salt Cyclic C6O4 Ammonium Salt 1190931-27-1 357.08 C6H4O6NF9 4.2 4.2.1 4.2.2 4.2.3 4.2.4 4.2.4 Chemicals and Reagents Acetone, AR Biosolve HFE7100 or 3MTMNovecTM Engineered Fluid HFE-7100 Composition : HFE-7100 fluid (C4F9OCH3) consist of two inseparable isomers with essentially identical properties. These are (CF3)CFCF2OCH3 (CAS No. 16702-08-7) and CF3CF2CF2- CF2OCH3 (CAS No. 163702-07-6) Supplier : 3MTM NovecTM Boiling point : 56C, HFE7100 is known to swell PTFE polymer Methanol : (Biosolve Cat no. 13680501 Lot no. 804911) Ammoniumacetate: (p.a. Merck) Water : MilliQ 4.3 Solutions 4.3.1 Stock solution of F-Diox Acid Ammonium Salt (4.19 mg/ml) Transfer 100 l of the F-Diox Acid Ammonium Salt solution in a 10 ml volumetric flask and fill to the mark with water. Mix carefully. 4.3.2 Diluted stock solution of F-Diox Acid Ammonium Salt (41.9 g/ml) Transfer 100 l of the stock solution (4.3.1) in a 10 ml volumetric flask. Fill the flask to the mark with water and mix carefully. TNO Triskelion Report | V20318 Annex 3 | 3 / 6 12 April 2013 4.3.3 Calibration solutions of F-Diox Acid Ammonium Salt (4 - 400 ng/ml) From the diluted stock solution (4.3.2), prepare calibration solutions containing 0.2, 0.4, 1.0, 2.0, 5.0 and 10 g of F-Diox Acid Ammonium Salt per ml water. Into a series of 10 ml volumetric flasks, transfer 1, 2, 5, 10 25, 50, 75 and 100 l of the diluted stocksolution of F-Diox Acid Ammonium Salt (4.3.2) and fill the volumetric flasks the mark with water. Mix the solutions thoroughly. The calibration solutions contain 4.19, 8.38, 20.95, 41.9, 104.75, 209.5, 314.25 and 419.0 ng F-Diox Acid Ammonium Salt/ml water. Fill the calibration solutions in LC vials. 5 Apparatus NOTE: An instrument or item of apparatus is listed only where it is special or made to a particular specification; usual laboratory glassware and equipment being assumed available. 5.1 LC-MS system whose main components include a liquid chromatographic system preferably with an automatic injector and a mass spectrometer (MS) detector operating in negative mode The following chromatographic conditions have been found suitable: LC apparatus: Orbitrap LTQ mass spectrometer (ThermoFisher Scientific, San Jose, CA, USA) equipped with an Ion Max ESI source, an Accela pump, an Accela autosampler and an Accela Photo Diode Array Detector. Flow injection ESI negative mode: Column: No column, only 1 m(L) x 0.25 mm (I.D) PEEK tubing as restriction Eluent: 50% Methanol + 0.1% NH4OH in MilliQ water Injection volume: 2 l Flow: 250 l/min Scan range: 125-1250 Monitoring ion: m/z 338.95 6 Sample preparation 6.1 Test sample preparation Establish the weight and the area of the test sample. Cut the test sample into small pieces, put it in an 200 ml erlenmeyer flask and reflux for 4 hours in 100 ml of a mixture of HFE7100/acetone (80/20). After 4 hours reflux, cool the solution down to room temperature. Take 1 ml of the extract, evaporate gently under a nitrogen stream to dryness and redissolve the residue 1 ml water. Fill a LC vial with the solution thus obtained. Treat blank extraction solvent, i.e. without polymer test sample, throughout the whole procedure. TNO Triskelion Report | V20318 Annex 3 | 4 / 6 12 April 2013 6.2 Recovery experiments Add a known amount of F-Diox Acid Ammonium Salt to 100 ml of a mixture of HFE7100/acetone (80/20), reflux for 4 hours. After 4 hours reflux, proceed as described for the test sample preparation as described in 6.1. 7 Procedure 7.1 Analysis NOTE: When starting measurements, baseline stability and response linearity of the detector should be examined, together with verification of the detection limit. The same operating conditions of the LC-MS system shall be maintained through out the analysis of all test samples and solutions set out in section 6. Each test sample shall be analysed at least in triplicate. 7.2 Sample treatment Test sample extracts, blanks, recovery samples, as well as calibration solutions are analysed by LC-MS. 7.2.1 Calibration solutions Inject each of the calibration solutions (4.3.3) into the LC system, using the conditions given in Section 5. Measure the peak area of the analyte in the chromatograms obtained and plot the area against the concentration of the analyte in the calibration samples in ng analyte per ml. NOTES: Two sets of calibration solutions made from independently prepared stock solutions should be cross-checked and should agree to 5 % of one another on the basis of peak ratio measurement. 7.2.2 Test samples and recovery solutions Inject each of the solutions obtained according to section 6.1 and 6.2 into the LC system, using the conditions given in Section 5. Measure the peak area of the analyte in the chromatogram obtained. 7.3 Quantification 7.3.1 Calculation of the analyte concentration in the test samples Graphical determination: Using the peak area values obtained from the test samples according to 7.2.2, read the analyte concentration in the extracts from the calibration graph (7.2.1) in ng/ml. Calculation from the regression parameters: TNO Triskelion Report | V20318 Annex 3 | 5 / 6 12 April 2013 Use the measured peak area as obtained in 7.2.2 in the following formula. If the regression line equation is linear y [peak area] = a * x [ng/ml] + b, with: y = detector response a = regression coefficient b = intercept x = concentration of the analyte then the analyte concentration in the solution C is Csol = (y-b)/a Both procedures yield directly the analyte concentration in the sample extracts in ng/ml NOTE: The method applying calculation from the regression parameters should be the preferred one. 7.3.2 Calculation of the residual content Calculate the residual content (QMA) of the analyte per 6 dm2 from the test sample as follows: QMA (mg/6 dm) = (Csol V 6)/(A x 106) In which: Csol (ng/ml) = concentration of the analyte in the tests sample extract injected for LC analysis; A (dm) = area of test sample extracted V = 100 ml (volume of extraction solvent) Calculate the residual content (QM) of the analyte per kg polymer from the test sample as follows: QM (mg/kg) = (Csol V)/(W x 103) In which: Csol (ng/ml) = concentration of the analyte in the tests sample extract injected for LC analysis; V = 100 ml (volume of extraction solvent W (g) = weight of test sample extracted TNO Triskelion Report | V20318 Annex 3 | 6 / 6 12 April 2013 8 Detection limit and precision 8.1 Detection limit The detection limit is based on the lowest calibration solution of 4 ng/ml. The signal to noise ratio for a solution containing 4 ng analyte/ml is higher than 3:1. 8.2 Recovery and repeatability The mean recovery and standard deviation were calculated from the recovery experiments with blank extraction solvent which was spiked with F-Diox Acid Ammonium Salt and subsequently refluxed for 4 hours (6.2). The recovery of F-Diox Acid Ammonium Salt at a spike level of 41.9 g/100 ml extract, after reflux for 4 hours in HFE7100/Acetone was found to be 124 5%. 8.3 Calibration curve The calibration curve should be linear. The correlation coefficient should be equal to or higher than 0.996. 9 Test report The test report shall contain, as a minimum, the following: - an identification - name of the laboratory - name of the person responsible for the analysis - date of the report - date of the analysis - chemical name of the analyte - a reference to the method of analysis - the performance characteristics of the method - sample details, such as: * type of food/food simulant/material/article * date of receipt of the sample, its origin and its denotation * date of preparation of the laboratory sample * conditions of storage of sample and laboratory sample - results expressed in mg analyte per 6 dm. - results should be reported as the average value from two or more determinations. - reasons for modification of the method of analysis, if applied