1、Designation: D7771 17Standard 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 consists of fused aromatic rings with no heteroatom orsubstituent.3.1.1.1 DiscussionPAHs naturally occur in oil, coal, an
8、dtar 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 So
9、xhlet-extracted withtoluene for 16 h. The extract is concentrated and subsequentlyanalyzed for BaP by gas chromatography with mass spectrom-etry (GC/MS). The BaP quantification is performed by themeans of an internal standard.5. Significance and Use5.1 This test procedure is used to determine the co
10、ncentra-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 70-cm3capacity. For instance, glass extraction t
11、himbleof 35-mm diameter by 90-mm height with course porosity (70to 100 m similar to Ace Glass Size C, Porosity B, Code-14).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.Curren
12、t edition approved Jan. 1, 2017. Published January 2017. Originallyapproved in 2011. Last previous edition approved in 2015 as D7771 15. DOI:10.1520/D7771-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of A
13、STMStandards 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.4Availa
14、ble 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 StatesThis international standard was developed in accordance with i
15、nternationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.16.3 Heating Mantle, compatible with boiling
16、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 extracted.6.6 PTFE or Glass Boiling Beads, approximately 3 mm.6.7 Glass Wool, need to be very clean or toluen
17、e 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 con-trolled water bath and nitrogen pressure control.6.10 Pear-Shaped Flasks for Rotary Evaporator, forex
18、ample, 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-umn composed of 5 % phenyl-methyl silicone coating is usedfor PAH analysis.6.11.3 Deactivated Straight Bor
19、osilicate 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 glass wool (4-mm internal diameter, straight liner).This shall be deactivated with a silanizing agent befor
20、e 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 produceacceptable results.6.11.5 Gold-plated seal for GC injector port or similarnonreactive seal.6.11.6 GC/MS amber
21、autosampler vials with polytetrafluo-roethylene (PTFE)-coated caps.6.11.7 Crimping tool.6.12 Adjustable Micropipettes, 1000, 200, and 20 L.6.13 Microliter 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 Vo
22、lumetric 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 down the coolingwhen the glassware is taken out of the muffle furnace.6.18 Furnace, capable of temperature re
23、gulation 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 ReagentsReagent-grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall
24、 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 first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the acc
25、uracy ofthe determination.7.2 Separate stock solutions of the native BaP standards andof the internal standard (deuterated or C13-labeled) can bepurchased as premade solutions or prepared from solid mate-rials (Table 1).7.2.1 A concentration range of 80 to 100 g/cm3for thenative BaP analyte stock so
26、lution is recommended.7.2.2 A similar concentration range of 80 to 100 g/cm3ofthe deuterated (d12-benzo-pyrene) or isotopically-labeled(13C4-benzo-pyrene) is recommended for the internal stan-dard (IS) stock solution.7.2.3 All purchased BaP standard materials shall be 98 %pure or better and certifie
27、d with respect to their purity andconcentration by the manufacturer. Follow the manufacturersrecommendation on how best to store the standard solutions.Typically, the compounds are protected from light. Theyshould be checked frequently for signs of degradation orevaporation. The BaP standard stock s
28、olutions shall bereplaced/recertified on a yearly basis or sooner if comparisonswith quality control (QC) samples indicate 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 analysis (99.99 % p
29、ure).7.5 Helium, GC/MS purity grade.7.6 Nitrogen, analytical purity grade.7.7 Silica gel columns for Solid Phase Extraction (SPE)removal of polar compounds.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagen
30、ts 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.TABLE 1 Native and Deuterated BaP CompoundsNative PAH CAS# De
31、uterated PAH CAS#C13 LabeledPAHCAS#Benzo-pyrene 50-32-8 d12-Benzo-pyrene 63466-71-7 13C4-Benzo-pyreneNot AvailableD7771 1727.7.1 Silica SPE Cartridges, single-use application, havinga volume capacity of approximately 1 to 10 cm3.67.7.1.1 Preparation of Silica SPE CartridgeFollow themanufacturers ins
32、truction for preparation and use. The typicalmethod of preparation is to wet the cartridge with approxi-mately 10 cm3of the elution solvent (toluene). Discard thewetting solvent.7.7.2 Alternative SPE Method: Silica Gel/13 % H2O Grav-ity Column:7.7.2.1 Preparation of a Silica Gel/13 % H2O AdsorbentPo
33、ur 200 g silica gel (high purity grade, type 60, particle size0.063 to 0.200 mm) into a screw cap glass bottle and add 30 gof deionized water in small portions (for example, 2 cm3) usinga suitable pipette. After addition of each portion of water, thesilica gel bottle is shaken to evenly distribute t
34、he wetted silicagel. No aggregation should occur during this process. If so,shaking must be continued until a homogeneous material isobtained. Finally, the closed bottle is shaken for 8 hours bymeans of an overhead shaker. If properly closed and stored, theadsorbent should be viable for at least 6 m
35、onths.7.7.2.2 Preparation of a Silica Gel/13 % H2O GravityColumnInsert a glass wool plug into the bottom of a pipettetip (for example, 8 to 10 mm inner diameter and 5 cm3capacity). Place1gofthesilica gel/13 % H2O in the columnand tap the column gently to settle the silica gel. Cover theadsorbent lay
36、er with a glass wool plug and pre-elute thecolumn with 5 cm3of cyclohexane. Discard the cyclohexaneeluate.8. 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
37、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 establishthe appropriate safety measures. Some PAH compounds havebeen shown to possess mutagenic as well as carcinogenic andteratog
38、enic properties.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 using five
39、solutionsof the native BaP and internal standard (IS). The recommendedBaP concentrations are to cover a range of 0.0125 to 1.0g/cm3(ppm). Other concentrations may be used as needed forthe application. The IS concentration is kept constant withinthe calibration range. Preferably the IS concentration
40、is in themiddle of the selected calibration range (for example, 0.3 to 0.6g/cm3). A lower BaP concentration range can be used for thecase of high-purity carbon blacks. However, the IS concentra-tion should maintain an S/N ratio of at least 15/1 for routineinstrument performance. Subsections 9.2 9.4
41、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 concentrations suggestedbelow. Other concen
42、trations may be used but the differencebetween any two concentration levels shall not exceed a factorof four. Before diluting to the final solution volume, spike eachstandard with the appropriate volume (for example, 100 L ISsolution described in 9.3) to give a final IS concentration of0.500 g/cm3.
43、Other aliquot volumes and final volumes may beused to obtain the desired concentrations. Cap the standardsolutions securely, mix thoroughly, and label.Native BaP Standard 5 1.00 g/cm3Native BaP Standard 4 0.500 g/cm3Native BaP Standard 3 0.200 g/cm3Native BaP Standard 2 0.0500 g/cm3Native BaP Standa
44、rd 1 0.0125 g/cm39.3 Preparation of Diluted IS SolutionUsing the IS stocksolution described in 7.2, prepare a convenient volume (forexample, 10 cm3) of diluted internal standard solution that willbe later added to samples and calibration standards. A concen-tration of 50.0 g/cm3is suggested for this
45、 diluted IS solutionin order to achieve a final concentration of 0.500 g/cm3in theextract sample.NOTE 1Other concentrations within the calibration range can be usedas well.9.4 All standard solutions shall be stored in amber glass-ware and kept in a refrigerator (6C) when not in use. Carehas to be ta
46、ken not to exceed their shelf life. If any indicationof degradation is perceived, then new standards have to beprepared.10. Carbon Black 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 s
47、trongly recommended to use separateglassware and extraction units for high-purity carbon blacksand carbon blacks in which higher BaP 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
48、 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 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
49、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 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 baked6The sole source of supply of the Sep-Pak cartridges known to the committee atthis time is Waters, 34 Maple Street, Milford, MA 01757 (). If youare aware of alternati
