1、Designation: D7771 17aStandard 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 re
2、vision. 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 arom
3、atic 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 use
5、r of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in
6、the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D4483 Practice for Evaluating Precision for Test MethodStandards in the R
7、ubber and Carbon Black ManufacturingIndustries2.2 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
8、.1 Definitions of Terms Specific to This 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 Discuss
9、ionPAHs naturally occur in oil, coal, andtar 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 M
10、ethod4.1 A portion of carbon black is Soxhlet-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 te
11、st 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.1This test method is under the jurisdiction of ASTM Committee D24 on Carb
12、onBlack and is the direct responsibility of Subcommittee D24.66 on Environment,Health, and Safety.Current edition approved Oct. 1, 2017. Published November 2017. Originallyapproved in 2011. Last previous edition approved in 2017 as D7771 17. DOI:10.1520/D7771-17A.2For referenced ASTM standards, visi
13、t 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 Protection Agency (EPA), ArielRios Bldg., 1200 Pennsy
14、lvania 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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, Wes
15、t Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Tr
16、ade Organization Technical Barriers to Trade (TBT) Committee.16.2 Extraction Thimbles, glass or cellulose, approximately50- to 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.
17、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 extracted.6.6 PTFE or Glass Boiling Beads, approximately 3 mm.6.7 G
18、lass 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 con-trolled water bath and nitrogen pressure control.6.10 Pear-
19、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-umn composed of 5 % phenyl-methyl silicone coating is usedfor PA
20、H 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 glass wool (4-mm internal diameter, straight liner).This shall be
21、 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 produceacceptable results.6.11.5 Gold-plated seal for GC injector port or s
22、imilarnonreactive 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 Microliter Syringes of Different Volumes, for example,10 and 100 L.6.14 Amber Glass Vials, approximately 4 cm3with
23、 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 down the coolingwhen the glassware is taken out of the muffle furna
24、ce.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 ReagentsReagent-grade chemicals shall beused in all tests. Unless o
25、therwise 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 first ascertained that the reagent is of sufficientlyhigh purity t
26、o permit its use without lessening the accuracy 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 1
27、00 g/cm3for thenative BaP analyte stock solution 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 material
28、s shall be 98 %pure or better and certified 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 degradati
29、on orevaporation. The BaP standard stock solutions 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 resoluti
30、on gas chromatogra-phy analysis (99.99 % pure).7.5 Helium, GC/MS purity grade.7.6 Nitrogen, analytical purity grade.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical So
31、ciety, 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# Deuterated PAH CAS#C13 LabeledPAHCAS#Benzo
32、-pyrene 50-32-8 d12-Benzo-pyrene 63466-71-7 13C4-Benzo-pyreneNot AvailableD7771 17a27.7 Silica gel columns for Solid Phase Extraction (SPE)removal of polar compounds.7.7.1 Silica SPE Cartridges, single-use application, havinga volume capacity of approximately 1 to 10 cm3.67.7.1.1 Preparation of Sili
33、ca SPE CartridgeFollow themanufacturers instruction 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 Prepa
34、ration of a Silica Gel/13 % H2O AdsorbentPour 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
35、gel bottle is shaken to evenly distribute the 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, the
36、adsorbent should be viable for at least 6 months.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 se
37、ttle the silica gel. Cover theadsorbent layer 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 associate
38、d 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 establishthe appropriate safety measures. Some PAH compounds havebeen shown to possess m
39、utagenic 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 personalprotection equipment (PPE) shall be used.9. Preparation of Standard Solutions9.1 The
40、 GC/MS instrument is calibrated using five 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 calibrat
41、ion range. Preferably the IS concentration 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 routinei
42、nstrument performance. Subsections 9.2 9.4 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
43、concentrations suggestedbelow. Other concentrations 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 gi
44、ve a final IS concentration of0.500 g/cm3. 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 B
45、aP Standard 2 0.0500 g/cm3Native BaP Standard 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
46、-tration of 50.0 g/cm3is suggested for this 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 refriger
47、ator (6C) when not in use. Carehas to be taken 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 ba
48、sis 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 be run on a regular basis.10.2 Glassware should be rinsed with toluene and acetoneafter us
49、e. 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 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 such as cellulose thimbles arerinsed with toluene and dried
