1、Designation:D777215Standard Test Method forCarbon Black Extractables Absorbance of CyclohexaneExtract1This standard is issued under the fixed designation D7772;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision
2、.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 method covers the determination of extinction(absorbance)of carbon black cyclohexane extract at 386 nmusing a UV spectrophotometer.
3、1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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 standard to establish appro-pr
4、iate 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 ManufacturingIndustries3.Summary of Test Method3.1 Acarbo
5、n black sample is gently agitated in cyclohexaneat room temperature to remove any extractable material.Themixture is left standing in the dark for 24 h at room tempera-ture.The carbon black is separated from the cyclohexane byfiltration,with subsequent determination of the extinction ofthe filtrate
6、at 386 nm using a 50-mm cuvette.4.Significance and Use4.1 This procedure serves as a screening process for carbonblacks used in the manufacturing of products that are to comeinto contact with food.The cyclohexane extract absorbance at386 nm must be less than 0.10 for a 50 mm cuvette in order tofulfi
7、ll various regulatory requirements.5.Apparatus5.1 Spectrophotometer,20 nm maximum spectral bandpass,capable of measuring absorbance at 386 nm.5.2 Cuvettes,with an optical light path of 50 mm.5.3 Balance,analytical,sensitivity 0.01 g.5.4 Filter Paper,with a particle retention in liquid less than2 m.5
8、.5 Glass Filtering Funnels,75 mm diameter at top.5.6 Volumetric Flask,100 cm3.5.7 Lens Cleaning Tissue,lint free.5.8 Timer,with 1 s divisions.5.9 Oven,gravity-convection type,capable of temperatureregulation of 125 6 5C.5.10 Desiccator.5.11 As a good laboratory practice,it could be suggested theuse
9、of a Neutral Density Filter with a spectral absorbancecalibrated at 386 nm to ensure the spectrophotometer iscorrectly calibrated.6.Reagents and Materials6.1 Cyclohexane,analytical reagent grade.7.Hazards7.1 This test involves hazardous materials,operations andequipment.This procedure does not attem
10、pt to address thesafety problems associated with this test.A hazards reviewmust be conducted by all personnel performing the test.It is theresponsibility of the user to review all MSDS,manuals andhazards procedures and establish the appropriate safety mea-sures.8.Calibration,Standardization,and Envi
11、ronmentalConditions8.1 Standard Laboratory Test Conditions: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 June 1,2015.Published September 2015.Originall
12、yapproved in 2011.Last previous edition approved in 2011 as D7772 11.DOI:10.1520/D7772-15.2For 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
13、page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 8.1.1 Unless stated elsewhere,all testing,calibration andstandardization should be carried out in the ambient tempera-ture range of 23 6 3C.8.1.2 The date of calibrat
14、ion or testing should also berecorded with any relevant data.8.1.3 All calibration data should be recorded on a dedicatedfile.8.2 Instrument Set-Up Frequency Day of Test:8.2.1 Turn on the spectrophotometer and allow it to warmup for 30 min.8.2.2 Set the wavelength to 386 nm and zero the instrument.8
15、.2.3 Place the Neutral Density Filter inside the samplecompartment of the instrument and verify the absorbance valueis within the absorbance tolerance.If the filter is found to beoutside the limits,verify the filters absorbance using a moresophisticated UV/Vis Spectrometer.If in this case nothingabn
16、ormal is found for the filter,service and calibrate thespectrophotometer.8.2.4 It is imperative that steps 8.2.5 8.2.8 are carried outin a fume hood using disposable nitrile gloves.This kind ofgloves are recommended for cyclohexane to prevent skinexposure(cyclohexane can cause skin irritation).8.2.5 Filter approximately 50 cm3cyclohexane through thefilter paper into a stoppered graduated cylinder.8.2.6 Transfer a portion of the filtered cyclohexane to aclean cuvette.The cuvette should not be han
