1、Designation: F 1308 98 (Reapproved 2008)Standard Test Method forQuantitating Volatile Extractables in Microwave SusceptorsUsed for Food Products1This standard is issued under the fixed designation F 1308; the number immediately following the designation indicates the year oforiginal adoption or, in
2、the case 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 complete microwave suscep-tors.1.2 This test method covers a
3、 procedure for quantitatingvolatile compounds whose identity has been established andwhich are evolved when a microwave susceptor sample istested under simulated use conditions.1.3 This test method was collaboratively evaluated with avariety of volatile compounds (see statistical evaluation). Forcom
4、pounds other than those evaluated, the analyst shoulddetermine the sensitivity and reproducibility of the method bycarrying out appropriate spike and recovery studies. Theanalyst is referred to Practice E 260 for guidance.1.4 For purposes of verifying the identity of or identifyingunknown volatile c
5、ompounds, the analyst is encouraged toincorporate techniques such as gas chromatography/mass spec-troscopy, gas chromatography/infrared spectroscopy, or othertechniques in conjunction with this test method.1.5 A sensitivity level of approximately 0.025 g/in.2isachievable for the compounds studied in
6、 Table 1. Where othercompounds are being quantitated and uncertainty exists overmethod sensitivity, the analyst is referred to Practice E 260 forprocedures on determining sensitivity of chromatographicmethods.1.6 The values stated in SI units are to be regarded asstandard. No other units of measurem
7、ent are included in thisstandard.1.7 This standard does not purport to address all of thesafety concerns, if any, associated 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 limitat
8、ions prior to use. Specific safetyhazards warnings are given in 10.2, 11.1, and 11.6.2. Referenced Documents2.1 ASTM Standards:2E 260 Practice for Packed Column Gas ChromatographyF 1317 Test Method for Calibration of Microwave Ovens2.2 TAPPI Standards:T 402 Standard conditioning and testing atmosphe
9、res forpaper, board, pulp handsheets, and related products3TIS 808 Equilibrium relative humidities over saturated saltsolutions33. Terminology3.1 Definitions:3.1.1 microwave susceptorsa packaging material which,when placed in a microwave field, interacts with the field andprovides heating for the pr
10、oducts the package contains.3.1.2 volatile extractablesthose chemical species whichare released from the microwave susceptor and can be detectedin the headspace under conditions simulating those underwhich the susceptor is used. Extractability does not necessarilymean migration of the extractable sp
11、ecies to the product beingheated on the susceptors.4. Summary of Test Method4.1 Volatile extractables are determined by subjecting asample of the susceptor material to microwave heating, fol-lowed by headspace sampling and gas chromatography. Quali-tative analysis may be carried out on a gas chromat
12、ograph(GC) coupled to an appropriate detector capable of compoundidentification. Volatile extractables are quantitated by compari-son with standards of known concentration.5. Significance and Use5.1 This test method is intended to measure volatile extract-ables that may be emitted from a microwave s
13、usceptor materialduring use. It may be a useful procedure to assist in minimizingthe amount of volatile extractables either through susceptordesign or manufacturing processes.5.2 Modification of this procedure by utilizing appropriatequalitative GC detection such as a mass spectrometer in place1This
14、 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 1990. Last previous edition approved in
15、 2003 as F 1308 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 website.3Available from Technical Associatio
16、n of the Pulp and Paper Industry (TAPPI),15 Technology Parkway South, Norcross, GA 30092, http:/www.tappi.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.of the flame ionization detector may provide identification ofvolatile extr
17、actables of unknown identity.6. Interferences6.1 Gas ChromatographyBecause of the potentially largenumber of chemical species that can be analyzed using thismethodology, not all species will be resolved from one anotheron a particular GC column under a given set of conditions.Techniques available to
18、 the analyst to verify the identity of thespecies being quantitated include retention time comparisonsusing alternate GC conditions or using an alternate GC columnto verify identification. Good judgement of chromatographicresults is always important.4,5,6Refer to Practice E 260 forguidance.6.2 Appar
19、atusBecause this test method is designed fortrace volatiles, and is highly sensitive, contaminants on vials,septa, syringes, etc. can lead to misinterpretation of results.Preparing apparatus properly and carrying out blank determi-nations as specified in the procedure is essential to minimizethis po
20、ssibility.7. Apparatus and Reagents7.1 Microwave OvenCalibrated, 7006 35 W, no turn-table. See Test Method F 1317.7.2 Humidity Chambers, operated at 50 % RH and 23C.7.2.1 Requirements for constant temperature-humiditychambers and equilibrium relative humidities over saturatedsalt solutions are outli
21、ned in TAPPI Methods T 402-om-88, andTIS 808-03.7.3 Vials, headspace, 20 mL (actual volume 21.5 mL). Toensure against extraneous peaks in the gas chromatographictraces, wash vials thoroughly and dry in a 125C air oven fora minimum of 4 h before using.7.4 Vial Crimp Caps.7.5 Septa, Polytetrafluoroeth
22、ylene (PTFE)/silicone. To en-sure that the septa are free of volatiles, cover the bottom of a15-cm petri dish with septa, PTFE-polymer side up. Micro-wave at full power for 10 min. Place microwaved septa into avacuum (greater than 29 in.) oven at 130C for 16 h.7.6 Crimping Tool for vials.7.7 Syringe
23、, 2 mL, gas-tight with valve. Store syringe in90C oven between uses.7.8 Gas Chromatograph equipped as follows:7.8.1 FID Detector, compatible with capillary columns.7.8.2 Injector, split/splitless compatible with capillary col-umns.7.8.3 Automated Headspace Sampler, Optional.7.8.4 Column, DB-5, 30 m,
24、 0.25-mm inside diameter, 1-mfilm thickness, or 0.32 mm. (A short piece of deactivated0.25-mm fused silica column may be placed between theinjector and the column to serve as a guard column.)7.8.5 Peak-Area Integration System compatible with GCsystem.Alternatively, a chart recorder and hand integrat
25、ion canbe used.7.9 Fluoroptic Thermometry System.7.10 Temperature Probes, high temperature.7.11 Beaker, 600 mL.7.12 Oven, hot air, set for 90C.7.13 Stopwatch.7.14 4-Heptanone.7.15 Standard SolutionsRegular Method:7.15.1 Internal Standard Solution (245 g/mL4-Heptanone)To approximately 950 mL of disti
26、lled water ina 1-L volumetric flask add 300 L of 4-heptanone. Mix welland dilute to volume with water.7.15.2 Standard Solution 1: (Prepare fresh daily.)To ap-proximately 475 mL of internal standard solution in a 500-mLvolumetric flask, add 50 L of each of the compounds to bequantitated. Mix well, an
27、d dilute to volume with internalstandard solution. If difficulty is experienced with dissolutionof analyte, alternate standard solution procedure may over-come this difficulty.7.15.3 Standard Solution 2Repeat 7.14.2 using 25 L ofeach compound.7.15.4 Standard Solution 3Repeat 7.14.2 using 10 L ofeach
28、 compound.7.16 Standard SolutionsAlternate Method:7.16.1 Alternate Internal Standard Solution (1225 g/mL4-Heptanone)To approximately 150 mL of helium-spargedorthodichlorobenzene (ODCB) in a 200-mL volumetric flaskadd 300 Lof 4-heptanone. Mix well and dilute to volume withODCB.4McCown, S. M., and Rad
29、enheimer, P., “An Equilibrium Headspace GasChromatographic Method for the Determination of Volatile Residues in VegetableOils and Fats,” LC/GC, Vol 7, No. 11, 1989, pp. 918924.5McNeal, T. P., and Breder, C. V., “Headspace Gas Chromatographic Determi-nation of Residual 1,3-Butadiene in Rubber-Modifie
30、d Plastics and Its Migrationfrom Plastic Containers Into Selected Foods,” Journal of the Association ofAnalytical Chemists, Vol 70, No. 1, 1987, pp. 1821.6McNeal, T. P., and Breder, C. V., “Headspace Sampling and Gas-SolidChromatographic Determination of Residual Acrylonitrile in Acrylonitrile Copol
31、y-mer Solutions,” Journal of the Association of Offcial Analytical Chemists, Vol 64,No. 2, 1981, pp. 270275.TABLE 1 Analyte Recovery Without MicrowavingCompound (n)ARecoveryMean, %WithinLaboratoryVariability, %OverallVariability, %Note(s)BBenzene 5 97.7 7.8 9.02-Butoxy-ethanol 4 98.7 6.7 8.4 1Dibuty
32、l Ether 5 109.7 16.5 23.7Dodecane 3 101.1 10.7 10.7 1, 22-Furfural 4 99.7 11.7 12.0 1Furan-2-Methanol3 100.0 14.1 16.4 1, 3Isobutyl Alcohol 4 96.0 7.1 7.9 4MethyleneChloride5 103.5 16.7 22.62-Propanol 3 99.9 11.4 12.0 4Styrene 5 100.8 8.5 9.3Toluene 4 102.7 9.9 10.9 4Overall 101.1 11.6 14.4An = numb
33、er of laboratories submitting data on compound.BNotes: Collaborating laboratories provided the following reasons for not sub-mitting data on a particular analyte:1. The analyst felt interaction was occurring among various analytes and spentseveral days investigating. The laboratory manager refused t
34、o allow additionaltime for collaborative study.2. The analyst questioned the solubility of the analyte and did not add to thespike mixture.3. A fresh standard was not prepared fresh daily. This compound degradesmeasurably in water in 24 h.4. The analyst experienced coelution of peaks under condition
35、s of collaborativestudy on his/her particular system.F 1308 98 (2008)27.16.2 Alternate Standard Solution 1 To approximately75 mL of alternate internal standard solution in a 100-mLvolumetric flask, add 50 L of each of the compounds to bequantitated. Mix well, and dilute to volume with alternateinter
36、nal standard solution.7.16.3 Alternate Standard Solution 2 Repeat 7.15.2 using25 L of each compound.7.16.4 Alternate Standard Solution 3 Repeat 7.15.2 using10 L of each compound.7.17 Susceptor BlankObtain a representative sample ofsusceptor material to be tested. Bake in an air oven overnightat 100C
37、 or higher to remove any volatile materials present.Store blank susceptor strips in humidity chamber 1 at 50 % RHand 23C until equilibrium moisture content is reached. Anexposure time of 24 h is generally adequate for most paper-based products. Strips should remain in the conditioningenvironment unt
38、il needed for analysis.7.18 Syringe Needle, 13 gage.7.19 Variable Voltage Transformer, OptionalThis can oc-casionally be used for minor adjustments to line voltage tobring power output of the microwave oven into the specifiedrange.8. Instrument Setup8.1 Determine sample test conditions as follows:8.
39、1.1 Set up microwave susceptor in the configuration of itsintended use, that is, a popcorn bag filled with popcorn, a pizzadisk with pizza on top, etc.8.1.2 Place temperature probes (7.10) on susceptor surface,disturbing the normal food load as little as possible. If thesusceptor has areas where the
40、 food does not normally contactthe surface, place the probes in these areas. Place the productin the center of the microwave oven.8.1.3 Cook the product in accordance with normal direc-tions, for the maximum cooking time. Record this time. Recordthe probe temperature(s), preferably at 5-s intervals,
41、 but atintervals not to exceed 15 s during cooking.8.1.4 Place 250 mL of room-temperature distilled water intoa 600-mL beaker. Place the beaker in the center rear of themicrowave oven.8.1.5 Cut a 10 by 65-mm (6.5-cm2= 1-in.2) portion from thesusceptor sample to be tested. Insert carefully into the 2
42、0-mLheadspace vial.8.1.6 Using a 13-gage syringe needle, pierce a hole into aheadspace vial septum. Place the septum on the vial and crimp.8.1.7 Insert one temperature probe (7.10) through the sep-tum hole into the vial and manipulate it until it is in contactwith the active face of the susceptor ma
43、terial. Place the vial onits side in the center of microwave oven, crimp end towardright of the oven, and susceptor with active face up.8.1.8 Microwave at full power, recording the probe tem-perature, preferably at 5-s intervals, but at intervals not toexceed 15 s.8.1.9 Plot the temperatures from 8.
44、1.3 and 8.1.8 on the samegraph.8.1.10 Compare the plots. If the trace from 8.1.8 closelyapproximates or is slightly higher than the plot from 8.1.3 thenthe test time will be equal to the maximum product cook timeof the product in that oven. If the trace is substantially higheror lower than that of t
45、he susceptor with product, then adjust themass or surface area, or both, (by changing container size) ofthe water (using a fresh sample of room temperature distilledwater) as necessary to achieve a similar profile. Record themass of water and type of container that gives the bestagreement between th
46、e test sample and the product temperatureprofiles.8.2 Set up the gas chromatographic system to meet thefollowing criteria.8.2.1 Injector Temperature250C.8.2.2 Detector Temperature250C.8.2.3 Column Temperature:8.2.3.1 Initial40C for 4 min.8.2.3.2 ProgramAdjust to give a retention window of:(1) At lea
47、st 15 min for volatile compounds bracketed by2-propanol and dichlorobenzene, retention time for 2-propanolof approximately 3 min and retention time for dichlorobenzeneof approximately 20 min.(2) Providing a separation of Di-n-butyl ether and styrene ofR = 0.5 or greater. For a 30-m by 0.25-mm column
48、 this isapproximately 4C/min with a nominal carrier flow of 1.5mL/min.8.2.4 Attenuation or sensitivity, or both, set to give aninternal standard peak height of 60 to 90% of full scale onrecorder or integrator.9. Sampling9.1 The sample of microwave susceptor selected for extrac-tion should be represe
49、ntative of the entire susceptor.9.2 The sample should be undamaged, that is, laminationintact, uncreased (unless this is normal configuration) andunaltered.9.3 Carefully cut a 10 by 65-mm (6.5 cm2= 1 in.2) portionfrom the susceptor. Carefully trim away any frayed edgesbefore testing. Store susceptor test strips in humidity chamber2 at 50 % RH and 23C until equilibrium moisture content isreached. An exposure time of 24 h is generally adequate formost paper-based products. Strips should remain in the condi-tioning environment until nee
