Document 4JEoJvXQRg41pMoGkEVawdkXN

TO "aymond A. Char tier at Aasonet, ^us, FROM Richard 'rendjrson at Eaven, Conn. 5OBJECT Imperial Cheaioal Industries Limited Analytical Methods for Vinyl Chloride Monomfr DATETebnu-ry 25, 1971* copy tcKs Roy Casque, P.D. S,, Cupach D. D. Pale A. w. sawyer beet D. B'. Smith Enclosed ere copies of analytical methods use-1 by 1 ape rial Chemical Industries, Ltd. for vinyl chloride nono*r in air, polyvinyl chloride realn and foodstuffs packaged in polyvinyl chloride. These nay contain sow information of use to you. Sl,*aph Enel. to R. Gvai* t.i i* n n p. i m Richard Henderaon Enel.- Copy of letter from A.W.Bames, ICI, to Subcommittee on Analytical Procedures, 2/11/71*. Copy of "The Determination of Vinyl Chloride Monomer in Non-Alcoholic and Alcoholic Drinks and Other Aqueous Solutions or Emulsions". Copy of "The Determination of Vinyl Chloride Monomer in Poly(Vinyl Chloride) Powders, Compounds and Mouldings* Headspace Sampling-Gas Chromatographic Method" Copy of "The Determination of Vinyl Chloride Monomer in Air Prototype Analyses using Flame Ionisation Detector" Copy of "The Determination of Vinyl Chloride Honorer in Poly(Vinyl Chloride) Latices, Slurries, Wet Cake and Powders* Solution Injection - Oas Chromatographic Jfethod" OL! 7659 WHY YlCC THIS CO^VI I* you MU1T DETAIN IT. 1PICIFT A DEFINITE DETENTION DEDIOSi ONI YEAD, imperial chemical industries limited PLASTICS DIVISION - WELVYN GARDEN CITY RESEARCH DEPARTMENT ANALYTICAL DIVISION THE DETERMINATION OF VINYL CHLORIDE MONOMER IN NON-ALCHOLIC AND ALCOHOLIC DRINKS AND OTHER AQUEOUS SOLUTIONS OR EMULSIONS INTRODUCTION The procedures described in this test method are those developed for the determination of low ppm quantities of vinyl chloride monomer leached from PVC bottles into the contained fluids during storage. The method employs a head space sampling gas chromatographic technique* calibrated by the addition of micro-litre quantities of a standardised solution of vinyl chloride in water, to samples of the particular fluid under test which have not been in contact with poly (vinyl chloride). INSTRUMENTATION The Perkin Elmer F40 Multifract head space sampling chromatograph is suitable. Set up the F40 assembly according to the manufacturer's instructions to (ipowf* under the conditions given in the table below. Use standard 25 "1 capacity F4q sample vials and seals and operate with an equilibration time of at least 3 hours at 30C before sampling. Column Column temperature 4 Metres 1/8" OD S.S. 20% w/w Carbowax 15 + 0.5$ Atpet 80 on silane treated (HMDS) Diatomrite C (60-72 mesh). 45C Water bath temperature 30C Injector needle temperature 120C Injection time Analysis time Purge time Stabilisation time Nitrogen carrier inlet pressure Air inlet pressure 5 see. Aqueous solutions (e.g. orange squash) 10 mins Gin, Vodka - 60 mins Whisky - 90 mins 24 sec 30 sec 1.0 Kp/cm2 V 1.2 Kp/cm2 OLI 7660 2- - Hydrogen inlet pressure 1.0 Kp/cifl^ Amplifier sensitivity 1x1 Recorder (2-pen) 2 mV and 10 or 20 mV. Chart speed 1 cm/min. An integrator can be used if desired. PREPARATION OF CALIBRATION SOLUTION Prepare a saturated solution of vinyl chloride in water at 25C. by the following method. Place the bubbler assembly shown in Fig. 1 into a water bath thermostatically controlled at 25C. Place 70 crn-^ water in the tube and bubble vinyl chloride through the absorber for a minimum period of 2 hours. Remove 10 cm^ of this solution into a 125 co^ Hypo-vial containing 90.0 cm^ distilled water. Immediately seal and store this dilute standard solution in a refrigerator at 5C. Remove two further 20 cm^ aliquots of the solution from the bubbler directly into the iodine flasks for standardisation as described below then transfer the remainder of this strong standard solution to a Hypo-vial and immediately seal and store in a refrigerator at 5C. STANDARDISATION OF STRONG STANDARD SOLUTION Solutions P.eouired Potassium bromide/bromate solution 0.1N Sodium thiosulphate solution 0.1N (standardised) Hydrochloric acid solution Approximately 2N Potassium iodide solution 20* w/v Method Into two* 250 em^ iodine flasks add 25*0 cm^ 0.1N potassium bromide/bromate solution. Add to each flask 20.0 car of the saturated vinyl chloride solution, from the bubbler and follow this by 15 ciik 2N hydrochloric acid solution. Immediately stopper the flasks, shake to mix the contents and seal the stopper with a little 20* potassium iodide solution. Allow the flasks to stand in the dark for at least 16 hours. Carefully remove the stopper allowing the potassium iodide to run into the flask, then add a further 10 cnr of the potassium iodide solution and titrate the liberated iodine with the 0.1N sodium thiosulphate solution. Carry out a blank on all the reagents used, using 20 cm^ distilled water instead of the aliquot of sample solution. Calculation * w/v vinyl chloride in solution \ - (Blank titre - sample 'titre) x 0.003125 x 1QO 20 OLI 7661 -3- In our experience the value so obtained should he about 0.15So w/v vinyl chloride. The .dilute standard solution is labelled at one tenth of this value. CALIBRATION OF GAS CHROMATOGRAPHIC PROCEDURE t3 Into a series of 25 cnr capacity F4o vials add 5 cm aliquots of the fluid under test which has not been in contact with poly(vinyl chloride). Seal and cap the vials and by means of a Hamilton micro-litre syringe add 0, 2, 5, 10, 20, 30, 70 and 100A"1 of the dilute standard vinyl chloride solution. Place the vials in the F40 thermostat bath at 30C and start the analysis, arranging the minimum 3 hours equilibration before the first standard is sampled by the chromatograph. Measure the peak height of the vinyl chloride peak shown in Fig, 2 for each standard and plot graphs relating peak height to/^g vinyl chloride per 5 cm^ solution. -These graphs cover the range 0 - 3/^g and 0 - 15/-S vinyl chloride per 5 cnr solution. EXAMINATION OF SAMPLES Shake each sample bottle and by means of a pipette transfer 5 cm^ to a 25 cm^ capacity F40 vial. Immediately seal and cap the vial and place it in the F40 thermostat bath at }0VC to be processed with a set of calibration standards as described above. RESULTS Measure the peak height due to vinyl chloride in the sample chromatogram and by reference to the appropriate calibration graph, calculate the vinyl chloride content of the liquid under test. Report the result as ppm w/v vinyl chloride. NOTE Most liquors contain "high boiling" constituents, and it is advisable to process no more than eight samples or standards at any one time. The column temperature should then be raised to about 100C and allow to purge clear of high boilers. An overnight purge carried out whilst a further set of samples or standards are equilibrating is convenient. If available, an electronic integrator may be used in conjunction with the chromatograph. 25 June 1973 DCMS/LEW/R-l/G \ OLI 7662 Virt-u. C.UOK ibL R$ l fe'v' f* r<. ^ or ri^O Du;CirRt, Ss'fiUHl C"Q c r 'V'IvItl C. rt LO< I T^f, flCtU'TM J OLI 7663 (A (A MM ConlIMT M !7\ 0'15 Irf FT& z PVC M..U.1 ti,7 r. (iOTTLr. rr 0 15 p p m /v - Cm 6\'j Pjotf*. r C ( <,iJl HOI *~5 Vin-fu C IUOH ll)t OLI 7664 io m o t |-i y '' iJ k H i.3