Document JJzZB6RdgDLMw31bLgJvX4eQO

DMl^itkA D 4443 - $4 AM A 1C AN SOCIETY f OB TESTING ANO MAT( niAl_S >916 Racu St.Philodatphia.Pa 19103 Rnni*d from m* Annual Book of ASTM SlmdiriH. CoOY'*gh< ASTM II not lifld iMh* cuini combinai indn. will appaar m p*4 nasi tdnion Standard Method for ANALYSIS FOR DETERMINING RESIDUAL VINYL CHLORIDE MONOMER CONTENT IN PPB RANGE IN VINYL CHLORIDE HOMO- AND CO-POLYMERS BY HEADSPACE GAS CHROMATOGRAPHY1 Tbis audvd ti imued tuds the bud dtwgwirinn D4443: the number immediately fcdkwmc the daigailiM iadiaia the yar of grippal adeyooo or.ta Ok case of rrvisoo, Ac year cflM icviaeo. A mba in parentheses iadicain the year of lam mpprpval. A snpemipt epailoe () iodicues an editorial dtaage ur the Im rrrimoa or (approval. 1. Scope 1.1 This method b suitable for determining the residual vinyl chloride monomer (RVM) con tent of bomopolymer and copolymers of vinyl chloride down to a level of --5 ppb. 1.2 This method b applicable to any polymer form, such as resin, compound, film, bottle wall, etc. that can be dissolved in a suitable solvent. 1.3 This standardmay involve hazardous ma terials, operations, and equipment. This standard does not purport to address all ofthe safetyprob lems associated with its use. It is the responsibil ity of whoever uses this standard to consult and establish appropriate safety and health practices and determinethe applicabilityofregulatory limi tations prior to use. Specific precautionary state ments are given in Section 9 and Note 13. 2. Applicable Document 2.1 OSHA Standard: 29CFR 1919.1017--Vinyl Chloride1 3. Seminary of Method 3.1 Samples of vinyl chloride containing pol ymers are dissolved in a suitable solvent in a dosed system. 3.2 The polymer solution and headspace axe equilibrated at an elevated temperature. 3.3 Aliquots ofheadspace gas are injected into a gas chromatograph and the vinyl chloride mon omer b separated. The response of vinyl chloride monomer b determined by the use of ooe of several suggested detectors. 3.4 Calibration b accomplished using either (a) vinyl chloride monomer in nitrogen gas standards, (b) standard solutions containing known amounts of vinyl chloride monomer, or (c) a method of standard addition. 4. Significance and Use 4.1 Vinyl chloride-containing polymers are widely used to package a variety of materials, including foods. 4.2 Vinyl chloride monomer has been shown to be a human carcinogen. Threshold toxicity value has not been established. 4.3 Plastic manufacturers, food packagers, government agencies, etc. have a need to know the residua] vinyl chloride monomer content of vinyl chloride-containing polymers. 5. Abbreviation 5.1 VCM--Vinyl chloride monomer. 5.2 DMAc--N,N<dimethylacetainide. .4 laterfereaces 6.1 DMAc should be analyzed to determine the absence of interferences at the vinyl chloride monomer gas chromatography (GQ retention time. 6.2 Other solvents, monomers, or compound- 1 Its netted ti under tbc juradtcaoo o(ASTM Committee D-20 oa nuba end tbe direct respoosbility ofSubcommittee D20.20 ob AnafyoaU Melted*. Curmi edition i^io^td Nov. 30. I9S4. Pubtecd Jinur) 1915. 1 Available from Superintendent of Documeno, US Go*n> moil Priamt Office. Washington. DC 20402. 1 20726001 b^G05053 {ft) 04440 ing aids may cause interference at the vinyl chlo ride monomer GC mention time 7. Apparatus 7.1 Gas Chromatography, equipped with either a flame ionization detector (FID), a photo ionization detector (PID). or a Hall electrcon ductivity detector (HED). backflushiog valve, and capable of either automatic (Note I) or man ual sampling (Note 2) and analyzing the head space vapors contained in a sealed vial. Note I--Perkio-Elrocr Model F-40, F-42, or F-4S Headspace Analyzer.1 backflushiog capabilities, ther mostatically controlled sample vial tray, and other re quired associated accessories can fulfill these require ments. Note 2--If the analyses are to be performed man ually. that is by syringe injection into other models of chromatographs, then the following equipment will also be needed: (/) Constant-temperature bath or oven capable of maintaining a temperature of 90 1*C. {2) Gas-tight GCsyringes for sampling and injection. (3) Sample bonks with fluoropolymer bees septa and caps (size optional). (4) Gloves for handling hot syringes. 7.2 Chromatographic Column, 3 % OV-101 on 80/100 mesh Chromosoxto WHP*, V6 is. (3.2 mm) outside diameter by 2 ft (0.6 m), stainless steel connected through V* in. "Tec'* to 0.19 % picric add on 80/100 mesh Carbopack C4,16 in. (3.2 mm) outside diameter by 8 ft (2.4 m), stain less sted. Note 3--Any column packing that wCD resolve VCM from interferences and dutc VCM in a reasonable length of time (I to 5 min) is satisfactory. For example, a 3 ft (0.9 m) by in. (3.2 mm) outride diameter column containing 0.19 % picric acid on 80/100 tnesb Carbopack C can replace the recommended 3 % OV 101 column. Settings recommended in 11 J.l may have to be modified to suit the packing material being used. 7.3 Two-Channel, I-mV. Full-Scale Re corder--A single-channel recorder is sufficient if the GC-detector signal is sent to a computer system or integrator to store the total VC peak area. An electronic integrator is recommended for measurement of peak areas. Non 4--Tbc VCM peak must be ket* on scale to manually measure the correct peak area or peak bright One method of achieving this without undue operator attention is to use a dual-channel recorder. One channel is set at a high sensitivity to obtain measurable-smaD peaks for low-VCM samples. Tbc other channel is set at a lower sensitivity to keep the larger peaks from highVCM samples on scale. 7.4 Detector Output Filter!Amplifier--Tbc extreme sensitivity of this method is best realized when the detector (usuall> operated at the ma*imum sensitivity) output is (a) filtered to remove the high-frequency noise and (6) amplified to give a visible or measurable signal. The filter/ amplifier is connected in series between the de tector and the recorder/computer. Note 5--A Spectrum Scientific Model 1021A filter/ampUfier* can fulfill these requirements. Other filter/ampliften may be available that are suitable. 7.3 Sample Headspace Vials, glass, 23 mL, with fluoropolymer-lined septa and aluminum caps. 7.6 Vial Sealer. 7.7 Analytical Balance, capable ofweighing to 0.001 g. 7.8 Statistical Programmable Calculator. Note 6--A programmable calculator is not abso lutely necessary, but can save a considerable amount of time when Urge numbers ofsamples are being analyzed. 8. Reagents and Materials 8.1 Vinyl Chloride Monomer (neat), pure, preferably in small cylinder. 8.2 Standard Cylinders, vinyl chloride mon omer in nitrogen at 1 and 10 ppm by volume. 8.3 Hydrogen Cylinder, prepurified gas. 8.4 Nitrogen, oxygen-free. Note 7--Helium may replace nitrogen as the car rier gas. 8.3 Air, breathing or water-pumped. 8.6 N.N-Dimethylacetamide (DMAc), sparged with nitrogen gas for up to a week at room temperature to remove chromatographic inter ferences. 9. Safety Precautions 9.1 Vinyl chloride monomer is a carcinogen and exposure by inhalation or dermal contact, or both, is to be avoided. Refer to OSHA Standard 29 CFR 1919.1017 for regulated levels of expo sure. DMAc is a teratogen. Tbc use of a properly functioning hood and septum-sealed sample con tainers are recommended. 9.2 Avoid all contact with heated pans of the gas chromatograph, hoi syringes, and sample bot tles. Handle all electrical connections with care. 'Aviitabe from PotoElaa Carp-. Miia Aw, Nomlk. CT 06356 * Cotuma packing a avaibbte from Supcfco. lee.. P.O. Box 62*, 146 S Water Sc, Bdtefeou. PA 16123 'Available from Spectrum SrieodAc Corp.. 2401 Opicuwm HA, Newark. DC 19711. 2 BFG05054  04443 9.3 Ones heated. sample vials are under pres sure After analysis, relieve ihc pressure with a hypodermic synngc needle vented into a charcoal slug or vent tube leading to a hood before remov ing vials from the water bath. 10. Sampling and Storage 10.1 Keep all polymer samples in lightly sealed jars or tightly wrapped aluminum foil prior to analysis. Dissolved polymer samples must be kept in septum-sealed vials or bottles until analyzed. Polymer solutions stored longer than 24 h should be maintained under refrigera tion. II. Preparation of Gas Chromatograph Note 8--All conditions in this section refer to the Perkin-Elmer Headspace Analyzer. If analyses are per formed manually, aher the operating procedures as required by the instrumentation. 11.1 Install the chromatographic column and condition overnight at HXTC, using normal car rier flow. Do not connect the exit end of the column to the detector or turn on detector gases during column conditioning. 11.2 Set the flow of detector gases as follows: Petefior FID FID HED Gas Hydrates Air Not required Hyditfti Flo* 30 lo 40 asVmis 300 to 400 aaVreis 30 cn'/mis 11.3 Set other parameters as follows: 11.3.1 Oven Temperature--50 to 6TC. Note 9--Higher oveo temperatures may be re quired wbeo other chromatographic columns are used, or when high-boiling solvents and laie-duting materials are being driven from the column. 11.3.2 Dosing Needle-- 150#C. 11.3.3 Injection Block Temperature--200*C. 11.3.4 Constant--Temperature Bath--90 .<rc. 11.3.5 Carrier--Gas Flow Bate--30 cm3/ min. Note I0--B^kflushing the carrier gas after VCM duies can considerably shorten analysis time. After bacUlushing. allow adequate time for chromatographic conditions to before making another injection. 11.3.6 Detector Temperature: 11.3.6.1 FID--2S0-C. 11.3.6.2 PID-- 150*C. 11.3.6.3 HED--MCTC. 11.3.7 Filter/Amplifier--Adjust as needed to remove high frequency noise and to provide ad equate amplification of VCM signal. Typical set tings: filter - 0.05 Hz and amplifier - 2x. 12. Calibration by Standard Addition Note 11--Tbe gas chromatograph is calibrated us ing either procedure: <o) VCM in nitrogen gas standards and a previously determined partition coefficient for VCM between DMAc and headspace, (b) VCM solu tion standards, or (r) a method of standard addition of VCM to polymer solutions. Procedure (c) is preferred to correct for any contribution tbe polymer makes to partitioning of VCM. Therefore, only procedure (f) is described. 12.1 Accurately weigh headspace vial, cap. and septum using an analytical balance. Add 20 mL DMAc to weighed vial. Cap loosely, and reweigh. In hood, prepare VCM stock solution in this vial by quickly uncapping vial and adding 0.4 to 2 g liquid VCM from inverted freezercooled cylinder of VCM. Immediately cap vial tightly and mix well by shaking.-Reweigh and calculate VCM concentration by weight (ca 20 000 to SO 000 ppm). Dilute this stock solution by withdrawing aliquots through septum with syringe and injecting into weighed, sealed vials of DMAc. Reweigh, and calculate VCM concen tration (ca 50 ppm). This solution is similarly diluted to yield solution containing 2 lo 5 ppm. Ifrefrigerated, these working standards are stable for several weeks. Multiple septum punctures shorten working life of standards. Non 12--Other methods of introdudug VCM into the DMAc may be satisfactory. These should be shows to be accurate and afe. 12.2 Add known volumes (jiLs) of the 1 lo 5 ppm VCM in DMAc standard to tbe polymer solutions prepared as described in Section. 13. Analyze solutions along with solvent blanks and the unknown, unspiked polymer solutions. 13. Procedure for Sample Analysis 13.1 Prepare two solvent blanks by adding 10.00 mL of DMAc to each oftbe two rials. Seal immediately with cap and septum. 13.2 Cut up polymer film and botlk samples into small (-5 by 5 mm) pieces. Use powder and pellet samples as received. 13.3 Prepare 8 viaK each containing the same weight, 0.01 g. of polymer (1.00 to 4.00 g depending on previously determined solubility or desired sensitivity. or both). Add 10.00 mL of DMAc to each rial and seal immediately with cap and septum. Begin vigorously disking vials 3 gpG05055 (ft) D 4443 at once to facilitate dissolution. Immerse vials in constant-temperature hath (90 * IT) until com plete solution is effected Vigorousl> shake vials occasional!) to aid solution. Alternatively, (/) immediately add a magnetic stirring bar to the vials and effect solution in an 85 to 95*C water bath on a stirring-type hot plate, or (2) place vials oo/in a reciprocating shaker and beat with a beat lamp. Note 13--VCM may be present in the atmosphere of laboratories located in or near PVC manufacturing plants and TVC fabricating plants. Therefore, it may be accessary to prepare the sealed rials ofsolvent blanks and sample mixtures inside a nitrogen-flushed glove box or glove bag to avoid contamination by xir-bom VCM. Once sealed, the vials can be returned to the laboratory atmosphere for the remainder of the analy sis. 13.4 After solution b attained (3 b), spike vials accordingly, using syringe through thick portion of septum: vials 1 and 2, no spike; vials 3 and 4, x jiL of I to 5 ppm VCM in DMAc standard (see 11.1) (x pL should give approxi mately double the GC response for VCM as in the unknown); vials 5 and 6, 2 x pL of I to 5 ppm VCM standard; and vials 7 and 8, 3 x pL of 1 to 5 ppm VCM standard. 13.5 Shake all vials to assure homogeneity. Heat vials in constant-temperature bath (90 IT) for ] h. 13.6 Adjust instrument injection time to in ject maximum amount of headspace gas from each vial into the gas chromatograph in the fol lowing sequence: solvent blank, 8, 6, 4, 2, I, 3, S, 7 solvent blank. NOTE 14--K may be useful to measure vial pressure after analysis but before removing vial from bath. This assures rial was correctly pressurized and no leaks occurred, either ofwhich will negate results. Note 15--Experience with the method and system or development, or both, of respocac factors fair one type of polymer may permit a reductioo in the number ofanalyses ofspiked unknowns during a determination. Nora 16--For manual injections, beat syringe to 90*C prior to withdrawing 1.0-mL headspace sample for injection. Wear gloves for protection. 13.7 Preparatory to plotting data points, con struct two perpendicular axes on linear graph paper. The units of the x-axis should be in terms of X. from -3x or less lo + 3* or more. The units of the y-axis should be from 0 to a positive value at least as large as the net average response value for vials 7 and 8. 13.8 Plot the net VCM response (average sam ple response for duplicate vials minus average blank response) for each vial pair on the y-axis versus the weight of VCM that was added to each member of the pair on the jr-axis. Draw the best straight line through the four points and extrap olate the line to intersect the x-axis. The distance from this point of intersection to the point X 0 on the x-axis is a measure of the VCM content of the sample. See Fig. I. Note 17--A computer program can be used to plot and extrapolate the data. 14. Calculation 14.1 Calculate the VCM content in the un known by determining the ng VCM obtained in the unknown (from the plot or computer) and dividing by the weight of polymer in the vial. Report findings in ppb (ng/g). 15. Precision and Bias4 15.1 The following values were determined for the coefficients of variation of this method on the basis of an interiaboratory test program (1981-82) involving 8 laboratories reporting re sults ofat least duplicate analyses: 15.2 Coefficient ofvariation (CV) at a residual vinyl chloride monomer level of approximately 10 ppb: CY for Copct- yuter Filai CV for Ho- mopotymer Pellets latraUboratory iMoUbonuiy 33.5 % 37.7 % 14.9 % 34.1 % 15.3 Bias--Since no absolute method is avail able for comparison, no statement can be pre sented for this method. *5wfjporaa( data are avmilabk oa loaa n A5TM Ha^quarten. Roques RJL D20-III6. T H )0 3 Z ia 4 BFG05056 n Cf 0 4443 -31 ?! -i 0 x 31 nsar c;vc.n i.r...i t | ^ n| VCH HG. I Soadftri AMMom Eunpotetfoa PM The American Societyft* Testing and Materials takes no position respecting the validity ofany patent rights assertedin connection with any urm mentioned in this standard L'sers ofthis standard art expressly advised that determination ofthe roltdayofany ruch patent nphis. and the nsk ofinfringement ofiurk rifAu. are entirety their own responsibility Thu standard is tybject to revision at any lime by ihr responsible technicalcommittee and must be reviewed everyfire years and if not tensed, either reapprtwed or withdrawn Your comments are mmed either for tension of this standard or far additional standards and should be addressed tv ASTM Headquarters Your comments will receive careful consideration at v meeting of the responsible technical committee, which you may attend If you feel that your comments ha*e not teethed a fair hearing you should makeyour news known to the ASTM Committee on Standards. 1910 Race St . Philadelphia. Pa. 19103 S00920 3f*G0505l M