1、Designation: F 1349 08Standard Test Method forNonvolatile Ultraviolet (UV) Absorbing Extractables fromMicrowave Susceptors1This standard is issued under the fixed designation F 1349; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、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) absorbing compo
3、nentsthat 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) suscep-tor. Adhe
4、sive 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, associated with its use.
5、 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:2F 874 Test Method for Temper
6、ature Measurement and Pro-filing for Microwave SusceptorsF 1317 Test Method for Calibration of Microwave Ovens3. Apparatus and Reagents3.1 Microwave Oven, 700 6 35 W, calibrated. Refer to TestMethod F 1317.3.2 High-Pressure Liquid Chromatograph (HPLC), consist-ing of:3.2.1 Pump, capable of 1.5 mL/mi
7、n 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 dimethylterephthalate DMT stand
8、ard.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 + 85 % water:a
9、cetonitrile.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 nonvolatiles ex
10、tractables 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).3.9 Diethylte
11、rephthalate (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 using.3.14 Recomm
12、ended Microwave Nonvolatile ExtractionCellWaldorf Polytetrafluoroethylene cell.3(See Figs. 1-3).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 re
13、sidual oil and prevent carry-over.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 Oct. 1, 2008. Published November 2008. Originallyapproved in
14、 1991. Last previous edition approved in 2003 as F 1349 98(2003).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 webs
15、ite.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 consideration
16、at a meeting of theresponsible technical committee,1which you may attend.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.NOTE 1The116-in. (1.6-mm) diameter hole is for a Luxtron MIWtemperature sensing probe. Number of holes and locat
17、ion may vary byapplication.FIG. 1 Collar Section of Waldorf PolytetrafluoroethyleneMicrowave Nonvolatile Extraction CellNOTE 1Relieve thread at bottom. Collar must seal to bottom of cap.FIG. 2 Cap Section of Waldorf Polytetrafluorethylene NonvolatileExtraction CellF13490823.15 Solvent Concentration
18、ApparatusKuderna-Danishevaporative 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 F 874 to determine the time andwater load specifications.4.2 Sample Preparati
19、on and Microwave Heating:NOTE 1Always 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 coldp
20、acks such as “blue ice.”4.2.1 Select 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 s
21、crew seal ring firmly seatedagainst 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. Alterna-tively, cut a 13 by 18-cm rectangular piece of the activesusceptor material, form an extrac
22、tion boat with sides 1.5 cmhigh (boat 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
23、 Measure the mass of the room-temperature 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 posit
24、ion for subsequent runs.4.2.5 Insert 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 con
25、tact with the extractionboat. Manipulate 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 F 874.Record the probe temperatures, preferably at 5-s i
26、ntervals, butat intervals not to exceed 15 s.4.3 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(see appendix) of the susceptor in DMAC. Proceed to generatechromatograms using high pressure l
27、iquid 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 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
28、 DMT versusconcentration.FIG. 3 Suggested Modifications to Waldorf CellF13490834.3.1.5 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 Extractables from Susceptor:4.3.2.1 Prepar
29、e 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 protective gloves. Severe burns can res
30、ult 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. Rinse the beakerwith 25 mL of acetonitrile a
31、nd 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 asecond 25-mL portion of acetonitrile, a
32、dd 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 bath in aKuderna-Danish evaporative con
33、centrator 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. Dilute sample if necessary if any extract
34、antpeaks 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 4.3.2.1-4.3.2.8.4.3.2.10 For reference, various oligomers o
35、f 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 chromatograms. Sum all the remaining peak areas
36、 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! / A (1)where:QA = quantity of component
37、 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).For the Waldorf Cell area circleA = 0.25pd2(53.52 cm2), and6.4516 =cm2/in.26. Report6
38、.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 representative sample time-temperature
39、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. Allsusceptor samples were prepared as extractio
40、n 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 determinationof PETE cyclic oligomers that migr
41、ated to corn oil. Table 2lists the values for the coefficients of variation of this testmethod 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 t
42、he WaldorfPTFE cell. 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
43、theintralaboratory RSDrand 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
44、. Of the data obtained from the two studies, onlythe total PETE oligomers determined after 5 min microwaveheating can be compared and are in reasonable agreement.TABLE 1 Determination and Deviations for PETE Oligomers ThatMigrated to Corn OilMean, mg/in.2Standard Deviation, mg/in.2Cyclic trimer 0.14
45、8 0.023Cyclic tetramer 0.021 0.006Cyclic pentamer 0.012 0.004Total oligomers 0.197 0.031F13490847.2 BiasSince no absolute method is available for com-parison, no statement can be presented for this test method.8. Keywords8.1 extraction cell, Waldorf; extractables, microwave sus-ceptors; extractables
46、, nonvolatile by HPLC; extractables, non-volatile UV absorbing; fat simulant, corn oil; fat simulant,Myglyol; fluoroptic thermometry; microwave susceptors;Myglyol; migration; nonvolatile extractables; nonvolatile ex-tractables, quantitation of, by HPLC; PETE; susceptors, mi-crowave, PETEAPPENDIX(Non
47、mandatory Information)X1. RECOMMENDED PRACTICEX1.1 Initially the total UV absorbing components presentin the polymer, adhesive, and paperboard should be deter-mined. This may be accomplished by shredding two 8 by 10-in.(20 by 25.4-cm), or equivalent, surface area susceptor sheetsand placing the shre
48、ds 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 few millilitres of residualsolvent rema
49、in, 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 any patent rights asserted in connection with a
