1、Designation: D7771 11Standard Test Method forDetermination of Benzo-a-Pyrene (BaP) Content in CarbonBlack1This standard is issued under the fixed designation D7771; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r
2、evision. 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 qualitative and quantitativedetermination of only benzo-a-pyrene (BaP), a specific poly-cyclic a
3、romatic hydrocarbon (PAH), on carbon black. Theprocedure involves Soxhlet extraction with toluene and analy-sis by gas chromatography with mass spectrometry (GC/MS).This method is not intended to test for U.S. Food and DrugAdministration (FDA) compliance of carbon blacks used forindirect food contac
4、t applications.1.2 UnitsThe values stated in SI units are to be regardedas the standard. No other units of measurement are included inthis standard.1.3 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 st
5、andard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D4527 Test Method for Carbon BlackSolvent Extract-ables2.2 EPA Standard:Method 8270D Semivolatile Organic Compounds by GasCh
6、romatography/Mass Spectrometry (GC/MS)32.3 Federal Standard:21 CFR 178.3297 Indirect Food Additives: Adjuvants, Pro-ductions Aids, and Sanitizers, Colorants for Polymers43. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 benzo-a-pyrene, BaP, nalso known as 3,4-benzopyrene or benz
7、o-a-pyrene is a specific polycyclic aro-matic hydrocarbon (PAH) or polynuclear aromatic hydrocar-bon that consist of fused aromatic rings with no heteroatom orsubstituent.3.1.1.1 DiscussionPAHs naturally occur in oil, coal, andtar deposits; are produced by the incomplete combustion ofhydrocarbons; a
8、nd occur in many other products and processes.BaP is a pentacyclic PAH with the formula C20H12, related topyrene by fusion of a phenylene group in the alpha position.4. Summary of Test Method4.1 A portion of carbon black is Soxhlet extracted withtoluene for a specified period of time. The resultant
9、extract ispurified by solid-phase extraction (SPE), concentrated down toa known volume, and subsequently analyzed for BaP by gaschromatography with mass spectrometry (GC/MS). The BaPquantification is performed by the means of a deuteratedinternal standard (isotope dilution).5. Significance and Use5.
10、1 This test procedure is used to determine the concentra-tion of BaP extracted from carbon black by the means of aSoxhlet extraction apparatus with toluene.6. Apparatus6.1 Soxhlet Extractor with Reflux Condenser, 50- or 100-cm3capacity.6.2 Extraction Thimbles, glass or cellulose, approximately50- to
11、 70-cm3capacity. For instance, glass extraction thimbleof 35-mm diameter by 90-mm height with course porosity (70to 100 m similar to Ace Glass Size C, Porosity B, Code-14).6.3 Heating Mantle, compatible with boiling flask describedin 6.4.6.4 Boiling Flasks for Soxhlet, for example, 250 cm3.6.5 Glass
12、 Beads, approximately 180 to 250 m (60/80mesh) if glass thimbles are used. Need to be very clean ortoluene extracted.6.6 PTFE or Glass Boiling Beads, approximately 3 mm.6.7 Glass Wool, need to be very clean or toluene extracted.6.8 Rotary Evaporator, with temperature-controlled waterbath, automatic
13、pressure regulation, and solvent-proof mem-brane vacuum pump.1This test method is under the jurisdiction of ASTM Committee D24 on CarbonBlack and is the direct responsibility of Subcommittee D24.66 on Environment,Health, and Safety.Current edition approved Nov. 1, 2011. Published December 2011. DOI:
14、10.1520/D7771-11.2For 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 United States Environmental
15、Protection Agency (EPA), ArielRios Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20004, http:/www.epa.gov/epaoswer/hazwaste/test/new-meth.htm#8270D.4Available from the U.S. Government Printing Office, Superintendent ofDocuments, 732 N. Capital St., NW., Washington, DC 20402-0001.1Copyright ASTM
16、International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.9 Nitrogen Blow-Down Apparatus, equipped with a con-trolled water bath and nitrogen pressure control.6.10 Pear-Shaped Flasks for Rotary Evaporator, for ex-ample, 25, 50, and 100 cm3.6.11 GC/MS, with
17、autosampler.6.11.1 MS with electron impact (EI) capability and single-ion monitoring (SIM) mode.6.11.2 GC Capillary Column, usually a nonpolar GC col-umn composed of 5 % phenyl-methyl silicone coating is usedfor PAH analysis.6.11.3 Deactivated Straight Borosilicate Liner with SmallPiece of Deactivat
18、ed Glass WoolThis liner may be used aslong as peak resolution is satisfactory.6.11.4 Alternative liner is a split/splitless nondeactivatedliner with glass wool (4-mm internal diameter, straight liner).This shall be deactivated with a silanizing agent before use.Another alternative is a split/splitle
19、ss liner with fluorocarbonliner seals. Such a liner will already contain conditionedsilanized glass wool. Other liners can be used if they produceacceptable results.6.11.5 Gold-plated seal for GC injector port or similarnonreactive seal.6.11.6 GC/MS amber autosampler vials with polytetrafluo-roethyl
20、ene (PTFE)-coated caps.6.11.7 Crimping tool.6.12 Adjustable Micropipettes, 1000, 200, and 20 L.6.13 Microlitre Syringes of Different Volumes, for example,10 and 100 L.6.14 Amber Glass Vials, approximately 4 cm3with caps(rubber with PTFE back).6.15 Amber Volumetric Flasks, 2, 3, 5, 10, 25, and 100 cm
21、3.6.16 Analytical Balance, with an accuracy of 0.01 mg.6.17 Drying Oven, gravity convection type, capable ofmaintaining 40 6 10C, used for slowing down the coolingwhen the glassware is taken out of the muffle furnace.6.18 Furnace, capable of temperature regulation of 500 625C, used to burn off organ
22、ic contamination from glasssurfaces.6.19 Manometer, capable of pressure readings in the rangeof 5 6 0.3 kPa.7. Reagents and Materials7.1 Purity of ReagentsReagent-grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of t
23、he Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.5Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.7.2 Separate stock
24、 solutions of the deuterated internal stan-dard (IS) and of the nondeuterated (native) BaP standards canbe purchased prepared from solid materials or individualsolutions (Table 1).Aconcentration range of 80 to 100 g/ cm3for both the native BaP and d12-benzo(a)pyrene is recom-mended. All purchased Ba
25、P standard materials shall be 98 %pure or better and certified in respect of their purity, concen-tration level, and authenticity by the manufacturer.7.2.1 Follow the manufacturers recommendation on howbest to store the standard stock solutions. It is generallyaccepted to keep them protected from li
26、ght. They should bechecked frequently for signs of degradation or evaporation,especially just before preparing calibration standards fromthem. The BaP standard stock solutions shall be replaced/recertified on a yearly basis or sooner if comparisons withquality control (QC) samples indicates a proble
27、m.7.3 Toluene, suitable for high resolution gas chromatogra-phy analysis (99.99% pure).7.4 Acetone, suitable for high resolution gas chromatogra-phy analysis (99.99% pure).7.5 Helium, GC/MS purity grade.7.6 Nitrogen, analytical purity grade.7.7 Silica Solid-Phase Extractor Cartridges, single-use ap-
28、plication, having a volume capacity of approximately 5 cm3or2- to 3-cm length by 1-cm diameter.68. Hazards8.1 This test involves hazardous materials, operations, andequipment. This procedure does not attempt to address thesafety problems associated with this test. A hazards reviewshall be conducted
29、by all personnel performing the test. It is theresponsibility of the user to review all material safety datasheets (MSDS), manuals, and hazards procedures and establishthe appropriate safety measures. Some PAH compounds havebeen shown to possess mutagenic as well as carcinogenic andteratogenic prope
30、rties.As such, concentrated extracts of carbonblacks containing PAHs also may possess the same harmfulproperties. Solvents used are flammable. Appropriate personalprotection equipment (PPE) shall be used.9. Preparation of Standard Solutions9.1 The GC/MS instrument is calibrated through five mix-ture
31、s of the native BaP and deuterated IS. The recommendedBaP concentrations are to cover a range of approximately 0.01to 0.8 g/cm3(ppm) while the IS concentration is kept constantat around 0.3 g/cm3. A lower BaP concentration range can beused for the case of high-purity carbon blacks, but thedifference
32、 between any two concentration levels shall notexceed a factor of four. Furthermore, the IS concentrationshould maintain an S/N ratio of at least 15/1 for routine5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of
33、reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial convention, Inc. (USPC), Rockville,MD.6The sole source of supply of the Sep-Pak cartridges kn
34、own to the committee atthis time is Waters, 34 Maple Street, Milford, MA 01757 (). If youare aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1which y
35、ou may attend.TABLE 1 Native and Deuterated BaP CompoundsPAH CAS# Deuterated PAH CAS#Benzo(a)pyrene 50-32-8 d12-Benzo(a)pyrene 63466-71-7D7771 112instrument performance. Subsections 9.2-9.5 describe thepreparation of the various solutions required.9.2 Preparation of Native BaP Standard Solutions for
36、CalibrationUsing the native BaP standard stock solutiondescribed in 7.2, prepare at least 10 cm3of five toluenesolutions in amber glassware at the concentrations suggested inthe following. Cap securely the standard solutions, mix thor-oughly, and label.Native BaP Standard 5 0.85 g/cm3Native BaP Stan
37、dard 4 0.28 g/cm3Native BaP Standard 3 0.09 g/cm3Native BaP Standard 2 0.03 g/cm3Native BaP Standard 1 0.01 g/cm39.3 Preparation of the Deuterated IS SolutionUsing thedeuterated IS stock solution described in 7.1, prepare at least50 cm3of a diluted toluene solution in amber glassware at theconcentra
38、tion suggested in the following. Cap securely thestandard solutions, mix thoroughly, and label.IS Standard 3.3 g/cm39.4 Preparation of the BaP Calibration SolutionsInto fiveseparate amber GC/MS vials, pipette 1.000 cm3of the nativeBaP standards prepared in 9.2 and 0.100 cm3of the IS standardsolution
39、 prepared in 9.3. Cap securely the amber GC/MS vials,mix thoroughly, and label. The following is obtained:Cal BaP 5 0.773 g/cm3native BaP + 0.300 g/cm3ISCal BaP 4 0.255 g/cm3native BaP + 0.300 g/cm3ISCal BaP 3 0.082 g/cm3native BaP + 0.300 g/cm3ISCal BaP 2 0.027 g/cm3native BaP + 0.300 g/cm3ISCal Ba
40、P 1 0.009 g/cm3native BaP + 0.300 g/cm3IS9.5 All standard solutions shall be stored in amber glass-ware and kept in a refrigerator (6C) when not in use. Carehas to be taken not to exceed their shelf life. If any indicationon degradation is perceived, the standard has to be preparedanew.10. Carbon Bl
41、ack Sample Preparation and Extraction10.1 All glassware parts coming into contact with thesample shall be BaP free on the basis of the limits ofquantification. It is strongly recommended to use separateglassware and extraction units for high-purity carbon blacksand carbon blacks in which higher BaP
42、levels are expected.Blanks should be run on a regular basis.10.2 Glassware should be rinsed with toluene and acetoneafter use. The glassware is then dried at 150C in a laboratorydrying oven.10.3 For low BaP carbon blacks, a pre-extraction of theextraction unit for at least4hisrecommended. If glassth
43、imbles are not baked in a furnace as described in 10.5, thenthe thimbles should be included in the 4 h pre-extraction.Cellulose thimbles should be included in the 4 h pre-extraction.In this case, the thimbles are further dried, for example, in avacuum drying oven prior to use.10.4 Disposable devices
44、 such as cellulose thimbles arerinsed with toluene and dried prior to use, for example, in avacuum oven.10.5 If repeated cleanings and extractions do not produceclean blanks, certain parts of the glassware may also be bakedfor at least 6 h in a furnace at, for example, 500C. This is alsovalid for gl
45、ass extraction thimbles if used. It shall be deter-mined with the manufacturer if the glass parts can sustain suchtemperaturefor example, it is unlikely the Soxhlet cansustain this.10.6 If glass extraction thimbles are used, they should bechecked for their drain rate at room temperature by pouring 5
46、0cm3of toluene inside the thimble. The time for 40 cm3to dripout of the thimble should not exceed 95 s. Otherwise, thethimble is to be discarded. Dry the thimbles with cleannitrogen.10.7 If glass extraction thimbles are used, pour the 60/80-mesh glass beads into the thimbles to a depth of 1 cm. Size
47、sother than 60/80 mesh may be used.10.8 Weigh 10 6 0.1 g to the nearest 1 mg of the beadedcarbon black sample into the dried extraction thimble. Recordthe exact value as WCB.10.8.1 Fluffy or powder carbon black should be densifiedwith toluene before extraction. This is accomplished by weigh-ing 10 6
48、 0.1 g of carbon black into a beaker and addingtoluene in approximately 1-cm3aliquots and mixing thetoluene into the carbon black with a spatula after each aliquotis added. This densifies the carbon black and forms pellets.Addsufficient toluene to densify the entire sample into crudepellets. The bea
49、kers shall then be left in the hood overnight toevaporate the solvent. Once the solvent has evaporated, breakup the larger of the carbon black pellets with a spatula. Theentire amount of pelletized black is then transferred to thethimble.10.9 Place a plug of glass wool or fold the top of thecellulose thimble above the black. The plug of wool should beplaced such that the glass wool is in contact with the carbonblack. This facilitates drainage of solvent through the glasswool and into the carbon black bed.10.10 Add a few glass boili
