1、Designation: F1349 08 (Reapproved 2014)Standard Test Method forNonvolatile Ultraviolet (UV) Absorbing Extractables fromMicrowave Susceptors1This standard is issued under the fixed designation F1349; the number immediately following the designation indicates the year oforiginal adoption or, in the ca
2、se of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of nonpolarand relatively polar ultraviolet (UV)
3、 absorbing componentsthat may migrate from microwave susceptor packaging intofood simulants, such as corn oil and Miglyol 812.1.2 This test method has been collaboratively studied usingbilaminate susceptors constructed of paperboard, adhesive, anda layer of polyethylene terephthalate polymer (PETE)
4、suscep-tor. Adhesive and PETE related compounds were quantitatedusing this test method.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associat
5、ed with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific warningstatements are given in 4.3.2.3.2. Referenced Documents2.1 ASTM Standards:2F874 Test Me
6、thod for Temperature Measurement and Pro-filing for Microwave SusceptorsF1317 Test Method for Calibration of Microwave Ovens3. Apparatus and Reagents3.1 Microwave Oven, 700 6 35 W, calibrated. Refer to TestMethod F1317.3.2 High-Pressure Liquid Chromatograph (HPLC), consist-ing of:3.2.1 Pump, capable
7、 of 1.5 mL/min with flow precision62%.3.2.2 Injector, loop-type, equipped with 20-L loop.3.2.3 Guard Column, C8, 5 m.3.2.4 Analytical Column, C8, 5 m, 250 by 4.6 mm.3.2.5 Detector-UV Absorbance, set for 254 nm. Adjustsensitivity to give a 70 to 100 % of full scale peak for the 5-ppm dimethylterephth
8、alate DMT standard.3.2.6 Gradient Program, 4 to 60 % Mobile Phase B in 8min; 60 to 70 % B in 9 min; 70 to 100 % B in 7 min; 100 % Bfor 11 min; 100 to 4 % B in 5 min; 4 % B for minimum of 5min. Where Mobile Phase A (v/v) is 85 + 15 + 0.25 %water:acetonitrile:acetic acid, and Mobile Phase B (v/v)is15
9、+ 85 % water:acetonitrile.3.2.7 Peak Area Integration SystemInitialize data acqui-sition or integration system, or both, from 5 to 35 min duringthe separation.3.3 Hexane, LC/UV grade.3.4 Acetonitrile, LC/UV grade.3.5 Corn OilObtain corn oil that is as pure and fresh aspossible to minimize peaks in n
10、onvolatiles extractables chro-matogram. Alternatively, Miglyol 812 (a fractionated coconutoil) or synthetic fat simulant HB 307 can be used as a substitutefor corn oil.3.6 Dimethylacetamide (DMAC), LC/UV grade.3.7 Conical Bottom Test Tubes, 50 mL, graduated.3.8 Bishydroxyethyleneterephthalate (BHET)
11、.3.9 Diethylterephthalate (DET).3.10 Dimethylterephthalate (DMT).3.11 Fluoroptic Thermometry System.3.12 Temperature Probes, four, high temperature.3.13 Glass Beads, 3 to 4 mm, clean thoroughly by rinsingwith methylene chloride followed by soaking for 30 min inacetonitrile. Dry thoroughly before usi
12、ng.1This test method is under the jurisdiction of ASTM Committee F02 on FlexibleBarrier Packaging and is the direct responsibility of Subcommittee F02.15 onChemical/Safety Properties.Current edition approved April 1, 2014. Published April 2014. Originallyapproved in 1991. Last previous edition appro
13、ved in 2008 as F1349 08. DOI:10.1520/F1349-08R14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright AS
14、TM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1NOTE 1The116-in. (1.6-mm) diameter hole is for a Luxtron MIWtemperature sensing probe. Number of holes and location may vary byapplication.FIG. 1 Collar Section of Waldorf Polytetrafluoroethylene Mi
15、cro-wave Nonvolatile Extraction CellNOTE 1Relieve thread at bottom. Collar must seal to bottom of cap.FIG. 2 Cap Section of Waldorf Polytetrafluorethylene NonvolatileExtraction CellF1349 08 (2014)23.14 Recommended Microwave Nonvolatile ExtractionCellWaldorf Polytetrafluoroethylene cell.3(See Figs. 1
16、-3).This cell must be constructed by a machine shop experiencedin working with polytetrafluoroethylene (PTFE). After micro-waving oil in the cell, the cell should be rinsed with methylenechloride to remove residual oil and prevent carry-over.3.15 Solvent Concentration ApparatusKuderna-Danishevaporat
17、ive concentrator, rotory evaporator; or Zymark Tur-boVap at a nitrogen pressure of 30 psi and a water bathtemperature of 50C.4. Procedure4.1 Temperature Measurement:4.1.1 Refer to Test Method F874 to determine the time andwater load specifications.4.2 Sample Preparation and Microwave Heating:NOTE 1A
18、lways be sure the microwave oven is at ambient temperaturebefore starting any temperature measurement or heating procedure toensure consistency of output. Cooling of the microwave oven can beexpedited by using ice in beakers or crystallization dishes or by using coldpacks such as “blue ice.”4.2.1 Se
19、lect a representative piece of the susceptor sampleto be tested. If the susceptor is part of a package, trim excessmaterial from around susceptor. Determine the area of theactive susceptor material. The susceptor should be cut to fit intoa Waldorf PTFE Cell with the screw seal ring firmly seatedagai
20、nst the susceptor surface. Use of the Waldorf PTFE cellreduces the risk of spilling hot oil and in addition, gives areproducible surface area (53.5 cm2) for extraction.Alternatively, cut a 13 by 18-cm rectangular piece of the activesusceptor material, form an extraction boat with sides 1.5 cmhigh (b
21、oat configuration = 1.5 by 10 by 15 cm, approximately150 cm2of surface area). Staple the corners of the boatsecurely.4.2.2 Add 53.2 g of Miglyol 812 of corn oil to the WaldorfPTFE Cell.Alternatively, add 22.5 g oil and 75 g of glass beadsto the extraction boat.4.2.3 Measure the mass of the room-temp
22、erature distilledwater load as determined in 4.1.1 into a 600-mL beaker andadd a boiling chip to this beaker.4.2.4 Place Waldorf PTFE Cell or extraction boat containingthe oil in the center of the microwave oven. Always positioncell/extraction boat in the same position for subsequent runs.4.2.5 Inse
23、rt the temperature sensing probes through pre-formed holes in the walls in Waldorf PTFE Cells (shown inFig. 1 and in the lower center sketch of Fig. 2), or in the caseof the extraction boat, tape the probe to the wall of the ovensuch that the probe tip maintains contact with the extractionboat. Mani
24、pulate the probes until they make good firm contactwith the active face of the susceptor material.4.2.6 Microwave the cell or alternate extraction boat usingthe time specifications as determined in Test Method F874.Record the probe temperatures, preferably at 5-s intervals, butat intervals not to ex
25、ceed 15 s.3The sole source of supply of the apparatus known to the committee at this timeis Read Plastics, 12331 Wilkins Ave., Rockville, MD 20852. If you are aware ofalternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive careful consider
26、ation at a meeting of theresponsible technical committee,1which you may attend.FIG. 3 Suggested Modifications to Waldorf CellF1349 08 (2014)34.3 Quantitative Analysis:4.3.1 Standard Curve:4.3.1.1 Prepare a standard mixture of 10 ppm (w/v) each ofBHET, DMT, DET, and any other identified UV components
27、(see appendix) of the susceptor in DMAC. Proceed to generatechromatograms using high pressure liquid chromatography inaccordance with 3.2.5, 3.2.6, and 4.3.2.8. Retention times forBHET, DMT, and DET will be approximately 7.6, 16.6, and21.5 min respectively.4.3.1.2 Repeat with a standard of 5 ppm of
28、DMT.4.3.1.3 Repeat with a standard of 1 ppm of DMT.4.3.1.4 Construct a plot of area response of DMT versusconcentration.4.3.1.5 For quantitation of PETE oligomers use the follow-ing response factor to construct an area response plot;(mass/area)DMT/( mass/area)Trimer= 0.912.4.3.2 Quantification of Ex
29、tractables from Susceptor:4.3.2.1 Prepare and place the sample in the microwave ovenin accordance with 4.2.1 4.2.6.4.3.2.2 Microwave at full power using the time determinedin 4.1.1.4.3.2.3 Stir oil in boat or cell. WarningBe extremelycareful when handling the Waldorf PTFE cell or extractionboat. Use
30、 protective gloves. Severe burns can result fromextremely hot oil.4.3.2.4 Weigh 3 6 0.03 g of stirred oil into a 50-mL beaker.Add 25 mL of hexane, stir, and transfer to a 125-mL separatoryfunnel.4.3.2.5 Rinse the beaker with an additional 25-mL portionof hexane and add to the separatory funnel. Rins
31、e the beakerwith 25 mL of acetonitrile and add to the separatory funnel.Shake the separatory funnel and draw off the acetonitrile phaseinto a 50-mL conical test tube or into a Kuderna-Danishevaporative concentrator with a 10-mL receiver or othersolvent concentration apparatus. Rinse the beaker with
32、asecond 25-mL portion of acetonitrile, add to the separatoryfunnel, shake, draw off acetonitrile, and add to the previousacetonitrile extract.4.3.2.6 Concentrate the combined acetonitrile extracts to 0.4to 0.5 mL in a 65C water bath under a gentle stream ofnitrogen or using a Turbo Vap or on a steam
33、 bath in aKuderna-Danish evaporative concentrator with a 10-mL re-ceiver and three-ball Snyder column.4.3.2.7 Cool, take residue in test tube to 2 mL with DMAC.4.3.2.8 Inject onto HPLC system, with or without filteringas desired, and separate using gradient conditions defined inapparatus in 3.2.6. D
34、ilute sample if necessary if any extractantpeaks are excessively large.4.3.2.9 To determine a Miglyol 812 or corn oil or blank,place the proper amount of oil in a borosilicate petri dish. Placea fresh susceptor in the oven, place the petri dish on thesusceptor and proceed through 4.3.2.1 4.3.2.8.4.3
35、.2.10 For reference, various oligomers of polyethyleneterephthalate (PETE) will have the following retention timesrelative to DET:cyclic trimer = 2.8tetramer = 5.2pentamer = 6.8hexamer = 7.8heptamer = 8.8octamer = 9.8nonamer = 10.24.3.2.11 Subtract blank oil peak contributions from thesample chromat
36、ograms. Sum all the remaining peak areas inthe sample chromatogram.4.3.2.12 Using the area versus concentration plot for DMT,find the quantity of extractables present in the concentratedcorn oil extract (QA ppm).5. Calculation5.1 Calculate susceptor extractables as follows:g/in.2! 5 6.4516QATO/OS!V!
37、/A (1)where:QA = quantity of component in oil extract, ppm,TO = total mass of oil in cell (53.5 g),OS = mass of oil sampled from boat or cell (3.00 g),V = final volume of concentrated extract, mL (2.0mL),A = surface area extracted, cm2(150 cm2for boat). Forthe Waldorf Cell area circle A = 0.25d2(53.
38、52cm2), and6.4516 =cm2/in.26. Report6.1 Report the following information:6.1.1 A representative sample chromatogram.6.1.2 The name and concentration in micrograms per squareinch of the individual migrants found in the oil. Include thedata for each sample analyzed and all replicate samples.6.1.3 A re
39、presentative sample time-temperature profile.7. Precision and Bias7.1 Precision:7.1.1 Two different microwave susceptor samples were usedin two separate collaborative studies. Both susceptors werelaminates of PETE-adhesive-paperboard.7.1.2 Six laboratories participated in the first study. Allsuscept
40、or samples were prepared as extraction boats (1.5 by 10by 15 cm) containing 22.5 g of corn oil and 75 g of glass beads.All susceptor samples were heated for a fixed time (5.0 min)using a fixed water load (250 g) in the microwave oven. Table1 lists the means and standard deviations for the determinat
41、ionof PETE cyclic oligomers that migrated to corn oil. Table 2lists the values for the coefficients of variation of this testTABLE 1 Determination and Deviations for PETE Oligomers ThatMigrated to Corn OilMean, mg/in.2Standard Deviation, mg/in.2Cyclic trimer 0.148 0.023Cyclic tetramer 0.021 0.006Cyc
42、lic pentamer 0.012 0.004Total oligomers 0.197 0.031F1349 08 (2014)4method for PETE oligomers based on the collaboration oflaboratories (1989) reporting triplicate analyses.7.1.3 In 1992, six laboratories participated in a secondstudy. All susceptor samples were evaluated using the WaldorfPTFE cell.
43、Susceptor samples were heated for 2 and 5 minusing a fixed water load (100 g). After concentrating, theextracts were analyzed for total PETE oligomers and diethyl-ene glycol dibenzoate (DEGDB) using HPLC with UV detec-tion.All analyses were performed in duplicate. Table 3 lists theintralaboratory RS
44、Drand interlaboratory RSDRfor total PETEoligomers and DEGDB determined in this study.7.1.4 The two studies had significant differences (differentsusceptor constructions, different water loads, and differentmicrowave heating times) and cannot be considered replicateinvestigations. Of the data obtaine
45、d from the two studies, onlythe total PETE oligomers determined after 5 min microwaveheating can be compared and are in reasonable agreement.7.2 BiasSince no absolute method is available forcomparison, no statement can be presented for this test method.8. Keywords8.1 extraction cell, Waldorf; extrac
46、tables, microwave sus-ceptors; extractables, nonvolatile by HPLC; extractables, non-volatile UV absorbing; fat simulant, corn oil; fat simulant,Myglyol; fluoroptic thermometry; microwave susceptors;Myglyol; migration; nonvolatile extractables; nonvolatileextractables, quantitation of, by HPLC; PETE;
47、 susceptors,microwave, PETEAPPENDIX(Nonmandatory Information)X1. RECOMMENDED PRACTICEX1.1 Initially the total UV absorbing components present inthe polymer, adhesive, and paperboard should be determined.This may be accomplished by shredding two 8 by 10-in. (20 by25.4-cm), or equivalent, surface area
48、 susceptor sheets andplacing the shreds in a Soxhlet extractor. This shreddedsusceptor is then serially Soxhlet extracted with hexane,chloroform, and acetonitrile (or similar solvents that will notdissolve the polymer) for 3 h each. After each 3-h interval, thesolvent is gently evaporated until a fe
49、w millilitres of residualsolvent remain, before the addition of the next solvent. Afterthe third solvent extraction, the solvent is concentrated andprepared for HPLC analysis using UV detection. This extractshould contain those UV absorbing materials that will poten-tially migrate to the corn oil under microwave heating condi-tions. Identification of unknown UV peaks can be performedby HPLC-mass spectrometry (MS) or by collecting the un-known HPLC peak and trying gas chromatography-MS.ASTM International takes no position respecting the validity of an
