1、Designation: F 1519 98 (Reapproved 2003)Standard Test Method forQualitative Analysis of Volatile Extractables in MicrowaveSusceptors Used to Heat Food Products1This standard is issued under the fixed designation F 1519; the number immediately following the designation indicates the year oforiginal a
2、doption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method is applicable to complete microwavesusceptors.1.2 T
3、his test method covers a procedure for identifyingvolatile extractables which are released when a microwavesusceptor sample is tested under simulated end use conditions.The extractables are identified using gas chromatography/massspectrometry (GC/MS).1.3 This test method was evaluated for the identi
4、fication ofa variety of volatile extractables at a level of 0.010 g/in.2ofsusceptor surface. For extractables not evaluated, the analystshould perform studies to determine the level of extractable atwhich identification is achievable.1.4 The analyst is encouraged to run known volatile extract-ables
5、and/or incorporate techniques such as gaschromatography/high resolution mass spectrometry (GC/HRMS), gas chromatography/infrared spectroscopy (GC/IR)or other techniques to aid in verifying the identity of oridentifying unknown volatile extractables. The analyst is re-ferred to Practice E 260 for add
6、itional guidance.1.5 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 limitations prior to us
7、e.2. Referenced Documents2.1 ASTM Standards:2E 260 Practice for Packed Column Gas ChromatographyF 874 Test Method for Temperature Measurement and Pro-filing for Microwave SusceptorsF 1308 Test Method for Quantitating Volatile Extractablesin Microwave Susceptors Used for Food ProductsF 1317 Test Meth
8、od for Calibration of Microwave Ovens3. Terminology3.1 Definitions:3.1.1 diffusion trappingthe collection of volatile extract-ables on an adsorbent by means of the mass diffusion of thevolatile extractables (1).33.1.2 microwave susceptorspackaging material which,when placed in a microwave field inte
9、racts with the field andprovides heating for the food products the package contains.3.1.3 volatile extractablesthose compounds that give 50 % recovery in spike and recovery studies using the appli-cable volatile extractables method. Extractability does notnecessarily imply migration of the extractab
10、le species to thefood product being heated on the susceptor.4. Summary of Test Method4.1 The volatile extractables are released from the susceptorwhen it has been heated to its end use heating conditions(temperature and heating time) using a thermostatically con-trolled oil bath or calibrated microw
11、ave oven. The releasedvolatile extractables are concentrated by diffusion trapping onan adsorbent. After adsorption is complete, the adsorbent isheated to desorb the volatile extractables onto a gas chromato-graphic column (Refs 17). The volatile extractables are thenseparated using a gas chromatogr
12、aph and detected by a massspectrometer. The volatile extractable identifications are con-firmed by comparing their retention times and mass spectra toreference compounds under identical GC/MS conditions.5. Significance and Use5.1 This test method is intended to identify volatile extract-ables that m
13、ay be emitted from microwave susceptor materialduring use. It may be a useful procedure to assist in minimizingthe amount and type of volatile extractables produced. The1This test method is under the jurisdiction of ASTM Committee F02 on FlexibleBarrier Materials and is the direct responsibility of
14、Subcommittee F02.15 onChemical/Safety Properties.Current edition approved Oct. 10, 1998. Published March 1999. Originallypublished as F 151994. Last previous edition F 151994.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For
15、 Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The boldface numbers in parentheses refer to a list of references at the end ofthis test method.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA
16、19428-2959, United States.susceptor design, materials used or manufacturing processesinvolved can be evaluated.6. Interferences6.1 Gas Chromatography/Mass SpectrometryThe GCconditions or column given may not exhibit sufficient resolu-tion to identify all the volatile extractables. Alternate tech-niq
17、ues should be used to identify the unresolved volatileextractables such as alternate GC conditions, an alternate GCcolumn, GC/HRMS, and/or GC/IR. The retention time andmass spectrum or infrared spectrum of the volatile extractableshould be verified with a reference standard.6.2 Apparatus and Materia
18、lsMethod interferences maybe caused by contamination from vials, septa, syringes, etc.,leading to misinterpretation of results at trace levels. All of thematerials must be routinely demonstrated to be free fromcontamination under conditions of the analysis by runningblanks.7. Apparatus and Reagents7
19、.1 Sample CutterNo. 14 cork borer.47.2 GlasswareWash all glassware thoroughly and dry in a125C air oven for a minimum of 4 h prior to using. Use nosolvents.7.2.1 Vials40 mL.57.2.2 Culture Tubes10by75mm.67.3 Vial CapsScrew caps for 7.2.1 vials.77.4 Vial SeptaPolytetrafluoroethylene PTFE faced silicon
20、backed septa, 22 mm diameter.8Place septa into a vacuumoven at 135C for 16 h prior to using.7.5 Volatile AdsorbentRefer to manufacturers literatureregarding physical, chemical, absorptive and desorptive char-acteristics of adsorbent.7.5.1 AdsorbentTenax TA, 35/60 mesh.97.5.2 ConditioningPlug one end
21、 of a 14 cm long, 6.35outside diameter by 5.3 mm inside diameter tube, premiumgrade 304 stainless steel10with a plug of silanized glasswool.11Fill tube with adsorbent, and plug other end withsilanized glass wool. Connect the tube to the injection portoutlet of the GC, set the UHP helium flow to 30 m
22、L/min andcondition adsorbent using the following program.Injection temperature 250CTemperature 1 70CTime 1 30 minRate 10C/minTemperature 2 250CTime 2 60 min7.5.3 StorageCap both ends of the tube after it cools,move to a chemical free area, uncap one end, remove glasswool, tap tube to transfer adsorb
23、ent to 40 mL glass vial, purgevial with UHP helium or argon for 1 min and seal with aconditioned PTFE/silicon septa (PTFE surface toward adsor-bent). Exercise care in handling the adsorbent.7.5.4 BlanksThe adsorbent should be tested for contami-nation prior to being used.7.6 Oil BathCirculating bath
24、 capable of being heated to250 6 1C.12Use silicone oil13to heat vials.7.7 ThermometersCapable of measuring up to 250C.14Calibrate thermometer with a NIST standardized thermom-eter15to ensure its accuracy.7.8 GC/MS System:7.8.1 Gas Chromatograph16, capable of temperature pro-gramming. The inlet carri
25、er gas line should be equipped with avalve17capable of being completely opened and closed within1s.7.8.2 The injector should have a removable glass liner orinsert, having a volume of at least 300 L or 40 mg ofadsorbent. The injector should have a closure that allows theliner/insert to be inserted an
26、d the injector sealed within 5 s.Modification of the injector may be required (2) through (6).7.8.3 GC Column60M Stabilwax, 0.25 mm ID, 0.5 mdf.187.8.4 Mass Spectrometer, capable of scanning from 35 to300 amu every2sorless when mass spectral data are obtainedin the electronimpact ionization mode at
27、a nominal electronenergy of 70 eV.197.8.5 Data SystemAn interfaced data system (DS) isrequired to acquire, store, reduce and output mass spectral data.The computer software must allow searching of any GC/MSdata file for ions of a specific nominal mass and plot itsabundance versus time or scan number
28、. This type of plot isdefined as an extracted ion current profile (EICP).7.9 Performance Volatile Standard for GC/MS System:7.9.1 Stock Volatile MixturePipet in accordance withTable 1 the appropriate volume into a 100 mL volumetric flaskwhich has been half filled with hexane. After all compoundshave
29、 been added, fill to mark with hexane and mix well.Alternate compounds may be substituted. Refrigerate mixtureat 4C until needed.7.9.2 Performance Volatile StandardDilute stock volatilemixture in step 7.9.1 1:1000 with hexane. Alternate dilutionsmay be made. Refrigerate standard at 4C until needed.7
30、.10 Susceptor BlankObtain a representative sample ofsusceptor material to be tested. Bake in an air oven overnightat 105C to remove any volatile extractables present. Store ina clean, sealed glass container (for example, desiccator) untilneeded.4Catalog No. 07-845E, Fisher Scientific, P.O. Box 4060,
31、 Plano, TX 75074, orequivalent.5Catalog No. 9534, Alltech Associates, Inc., 2051 Waukegan Rd., Deerfield, IL60015, or equivalent.6Catalog No. 14-962-10A, Fisher Scientific, or equivalent.7Catalog No. 95321, Alltech Associates, Inc., or equivalent.8Catalog No. 95322, Alltech Associates, Inc., or equi
32、valent.9Catalog No. 04915 and 049151, Alltech Associates, Inc., or equivalent.10Catalog No. 303010ST, Alltech Associates, Inc., or equivalent.11Catalog No. 4038, Alltech Associates, Inc., or equivalent.12Catalog No. L-01268-52, Cole Palmer Instrument Company, 7425 North OakPark Ave., Chicago, IL 606
33、48, or equivalent.13Catalog No. L-01294-00, Cole Palmer Instrument Co., or equivalent.14Catalog No. 14-995-5#, Fisher Scientific, or equivalent.15Catalog No. 15041D, Fisher Scientific, or equivalent.165890 Gas Chromatograph, Hewlett Packard Company, 3000 Hanover St., PaloAlto, CA 94304, or equivalen
34、t.17Catalog No. 2328, Alltech Associates, Inc., or equivalent.18Catalog No. 10641, Restek Corp., Penn Eagle Industrial Park, 100 BennerCircle, Bellefonte, PA 16823-8812, or equivalent.195971A Mass Selective Detector, Hewlett Packard Company, 3000 HanoverStreet, Palo Alto, CA 94304, or equivalent.F 1
35、519 98 (2003)27.11 Heliumultra high purity (UHP).207.12 Calibrated Ovensee Test Method F 1317.8. Instrument Set-up8.1 Setup the GC/MS/DS to meet the following criteria.Alternate conditions can be used to resolve unidentified vola-tile compounds.Temperature 1 40CTime 1 3 minRate 10/minTemperature 2 2
36、10CTime 2 15 minCarrier gas flow 10 mL/min UHP heliumInjector Temperature 250CDetector electron multiplierInterface temperature 250CMass scanned 35250 amuIonization voltage 70 eV9. Daily GC/MS Performance Check9.1 Tune the mass spectrometer in accordance with theinstrument manufacturers procedure.9.
37、2 Inject 1 L (approximately 14 to 18 ng of each volatileis injected) of the performance volatile standard (see 7.9.2)toverify chromatographic retention times and mass spectra pro-duced using conditions in Section 8.Atypical chromatogram isshown in Fig. 1. As a minimum, the ions listed in Table 1shou
38、ld be present and in their expected ratios for each volatilelisted.9.3 Repeat 9.1 and 9.2 until these conditions are met prior torunning any sample.10. Sampling10.1 Microwave susceptor sample selected for extractionshould be representative of the entire susceptor.10.2 Sample should be undamaged, tha
39、t is, laminationintact, uncreased (unless this is its normal configuration), andunaltered.10.3 Carefully cut a 0.75-in. diameter circular portion fromthe susceptor using a cork borer. Carefully trim away anyfrayed edges before extracting.11. Procedure11.1 Insert sample from 10.3 carefully into 40 mL
40、 vial.11.2 Place enough conditioned Tenax-GC (approximately avolume of 250 L or 40 mg) into a 10 by 75 mm culture tubeand place it in vial with susceptor.11.3 Immediately place septa over vial (PTFE side towardsample) and cap.11.4 Place vial in an oil bath maintained at 218 6 1C (4256 2F) for 5 min.
41、 The oil bath temperature should be verifiedusing a calibrated thermometer. The temperature and time thesample is to be heated can be established using Test MethodsF 874 and F 1317. Alternately Test Method F 1308 can be usedfor heating the susceptor.11.5 After heating, remove vial from oil bath and
42、place in a35C oven for 16 hours.11.6 Pour the Tenex GC from the culture tube into a GCinjection port liner (see 7.8.2). A small funnel equipped with ashort piece of plastic tubing will aid in the transfer. Place a plugof silanized glass wool into the other end of the liner to retainthe Tenax.11.7 Tu
43、rn off the carrier gas to the GC by using the inlettoggle valve.11.8 As quickly as possible, remove the cap from theinjector, place the liner in the injector port, replace the cap andturn the carrier flow on.20UHP Helium, Matheson Gas Products, PO Box 87, Hasbrouck Heights, NJ07604.TABLE 1 Stock Vol
44、atile MixturePreparation and CharacteristicIons, m/z, for Each VolatileCompound Volume Pipetted, mLACharacteristic Ions,m/z2-Methyl furan 1.7 82, 81, 53Benzene 1.7 78, 77, 52n-Propyl acetate 1.7 73, 43Trichloroethylene 1.0 130, 95Hexanal 2.0 56, 72, 82n-Butyl alcohol 2.0 43, 41, 56n-Butyl acrylate 1
45、.7 55, 73, 85Dodecane 2.0 57, 71, 85Styrene 1.7 104, 103, 781,4-Dichlorobutane 1.5 55, 90N,N-Dimethylformamide 1.5 73, 44, 42Furfural 1.5 95, 96Benzaldehyde 1.5 106, 105, 77Pentanoic acid 1.5 73, 602-(2-Butoxyethoxy)-ethanol1.5 45, 57, 75APipet into 100 mL volumetric flask which has been half filled
46、 with hexane.Number Compound1 2-Methyl Furan2 Benzene3 n-Propyl Acetate4 Trichloroethylene5 Hexanal6 n-Butyl Alcohol7 n-Butyl Acrylate8 Dodecane9 Styrene10 1,4-Dichlorobutane11 N,N-Dimethylformamide12 Furfural13 Benzaldehyde14 Pentanoic Acid15 2-(2-Butoxyethoxy)-EthanolFIG. 1 Total Ion Chromatogram
47、of Performance VolatileStandardF 1519 98 (2003)311.9 Activate the GC program.11.10 Chromatograph the sample using the conditions givenin Section 8.11.11 A vial containing only the Tenax in a culture tubeshould be carried through the entire procedure to identifypotential artifactual peaks (7).12. Vol
48、atile Extractable Identification12.1 From the data obtained from Section 11, obtain a massspectrum for the volatile extractable of interest. A backgroundspectrum should be taken just before or after each volatileextractable elutes and subtracted from the volatile extractablespectrum to minimize mass
49、 spectral interferences.12.2 Using a suitable reference library (8), search and findthe best match for the volatile extractable mass spectrum inquestion.Note: CautionIf several volatile extractables are presentin the sample and coelute, the resulting spectrum will representa composite. Alternate techniques may be needed to get asuitable mass spectrum of the volatile extractable of interest.12.3 Using the same instrumental conditions that were usedto analyze the sample, collect the mass spectra of authenticreference compounds.
