1、Designation: D7771 13Standard Test Method forDetermination of Benzo-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 rev
2、ision. 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-pyrene (BaP), a specific poly-cyclic aroma
3、tic 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 (FDA21 CFR 178.3297) compliance of carbonblacks used for indirect
4、food contact 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
5、 of this standard 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:2D4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndu
6、stries2.2 EPA Standard:3Method 8270D Semivolatile Organic Compounds by GasChromatography/Mass Spectrometry (GC/MS)2.3 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
7、 Standard:3.1.1 benzo-pyrene, BaP, nalso known as 3,4-benzopyrene or benzo-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, and
8、tar deposits; are produced by the incomplete combustion ofhydrocarbons; and 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 Sox
9、hlet extracted withtoluene for a specified period of time. The resultant 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
10、 deuteratedinternal standard (isotope dilution).5. Significance and Use5.1 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-cm3
11、capacity.6.2 Extraction Thimbles, glass or cellulose, approximately50- to 70-cm3capacity. For instance, glass extraction thimble1This 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.C
12、urrent edition approved Nov. 1, 2013. Published November 2013. Originallyapproved in 2011. Last previous edition approved in 2011 as D7771 11. DOI:10.1520/D7771-13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Boo
13、k of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from United States Environmental Protection Agency (EPA), ArielRios Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20004, http:/www.epa.gov/epaoswer/hazwaste/test/new-meth.htm#8270D.4
14、Available from the U.S. Government Printing Office, Superintendent ofDocuments, 732 N. Capital St., NW., Washington, DC 20402-0001.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1of 35-mm diameter by 90-mm height with course porosity
15、(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 Beads, approximately 180 to 250 m (60/80mesh) if glass thimbles are used. Need to be very clean ortoluene ext
16、racted.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 pressure regulation, and solvent-proof mem-brane vacuum pump.6.9 Nitrogen Blow-Down Apparatus, equipped with a
17、 con-trolled water bath and nitrogen pressure control.6.10 Pear-Shaped Flasks for Rotary Evaporator, forexample, 25, 50, and 100 cm3.6.11 GC/MS, with 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-
18、umn composed of 5 % phenyl-methyl silicone coating is usedfor PAH analysis.6.11.3 Deactivated Straight Borosilicate Liner with SmallPiece of Deactivated Glass WoolThis liner may be used aslong as peak resolution is satisfactory.6.11.4 Alternative liner is a split/splitless nondeactivatedliner with g
19、lass wool (4-mm internal diameter, straight liner).This shall be deactivated with a silanizing agent before use.Another alternative is a split/splitless liner with fluorocarbonliner seals. Such a liner will already contain conditionedsilanized glass wool. Other liners can be used if they produceacce
20、ptable results.6.11.5 Gold-plated seal for GC injector port or similarnonreactive seal.6.11.6 GC/MS amber autosampler vials with polytetrafluo-roethylene (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 exam
21、ple,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 cm3.6.16 Analytical Balance, with an accuracy of 0.01 mg.6.17 Drying Oven, gravity convection type, capable ofmaintaining 40 6 10C, used for slowing dow
22、n 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 organic 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 Rea
23、gentsReagent-grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.5Other grades may be used,provided it is fi
24、rst ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.7.2 Separate stock solutions of the deuterated internal stan-dard (IS) and of the nondeuterated (native) BaP standards canbe purchased prepared from solid materials or
25、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 BaP standard materials shall be 98 %pure or better and certified in respect of their purity, concen-tration level, and authenticity by the manufacturer.
26、7.2.1 Follow the manufacturers recommendation on howbest to store the standard stock solutions. It is generallyaccepted to keep them protected from light. They should bechecked frequently for signs of degradation or evaporation,especially just before preparing calibration standards fromthem. The BaP
27、 standard stock solutions shall be replaced/recertified on a yearly basis or sooner if comparisons withquality control (QC) samples indicates a problem.7.3 Toluene, suitable for high resolution gas chromatogra-phy analysis (99.99% pure).7.4 Acetone, suitable for high resolution gas chromatogra-phy a
28、nalysis (99.99% pure).7.5 Helium, GC/MS purity grade.7.6 Nitrogen, analytical purity grade.7.7 Silica Solid-Phase Extractor Cartridges, single-useapplication, having a volume capacity of approximately 5 cm3or 2- to 3-cm length by 1-cm diameter.68. Hazards8.1 This test involves hazardous materials, o
29、perations, andequipment. This procedure does not attempt to address the5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChe
30、micals, 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 known to the committee atthis time is Waters, 34 Maple Street, Milford, MA 01757 (). If youar
31、e 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 you may attend.TABLE 1 Native and Deuterated BaP CompoundsPAH CAS# Deuterated PAH CAS#Benzo(
32、a)pyrene 50-32-8 d12-Benzo(a)pyrene 63466-71-7D7771 132safety problems associated with this test. A hazards reviewshall be conducted by all personnel performing the test. It is theresponsibility of the user to review all material safety datasheets (MSDS), manuals, and hazards procedures and establis
33、hthe appropriate safety measures. Some PAH compounds havebeen shown to possess mutagenic as well as carcinogenic andteratogenic properties.As such, concentrated extracts of carbonblacks containing PAHs also may possess the same harmfulproperties. Solvents used are flammable. Appropriate personalprot
34、ection equipment (PPE) shall be used.9. Preparation of Standard Solutions9.1 The GC/MS instrument is calibrated through five mix-tures 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
35、 constantat around 0.3 g/cm3. A lower BaP concentration range can beused for the case of high-purity carbon blacks, but thedifference 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 routineinstr
36、ument performance. Subsections 9.2 9.5 describe thepreparation of the various solutions required.9.2 Preparation of Native BaP Standard Solutions forCalibrationUsing the native BaP standard stock solutiondescribed in 7.2, prepare at least 10 cm3of five toluenesolutions in amber glassware at the conc
37、entrations suggested inthe following. Cap securely the standard solutions, mixthoroughly, and label.Native BaP Standard 5 0.85 g/cm3Native BaP Standard 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 Sol
38、utionUsing thedeuterated IS stock solution described in 7.1, prepare at least50 cm3of a diluted toluene solution in amber glassware at theconcentration suggested in the following. Cap securely thestandard solutions, mix thoroughly, and label. This recommen-dation on the use of an internal standard i
39、s consistent with thepractice described in EPA Method 8270D.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 prepared in 9.3. Cap securely the
40、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 BaP 1 0.009 g/cm3native BaP + 0.300 g
41、/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 Black Sample Preparation and Extracti
42、on10.1 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 levels are expected.Blanks should b
43、e 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 glassthimbles are not baked in a furnace a
44、s 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 such as cellulose thimbles arerins
45、ed 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 glass extraction thimbles if used. It
46、 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 50cm3of toluene inside the thimble.
47、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. Sizesother than 60/80 mesh may be used.
48、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 0.1 g of carbon black into a beake
49、r 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 beakers 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 glas
