1、Designation:D622906(Reapproved 2010)Standard Test Method forTrace Benzene in Hydrocarbon Solvents by Capillary GasChromatography1This standard is issued under the fixed designation D6229;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revisio
2、n,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method covers the determination by capillarygas chromatography of trace benzene in hydrocarbon sol
3、ventsat levels from 1.0 to 2400 vppm.NOTE1Lower levels of benzene may be determined by this testmethod.However the gas chromatography(GC)will have to be modifiedfrom those specified in this test method.The precision of the method maynot apply to these lower benzene levels.1.2 For hazard information
4、and guidance,see the suppliersMaterial Safety Data Sheet.1.3 The values stated in SI units are to be regarded as thestatement.The values in parenthesis are given for informationonly and are not necessarily the exact equivalent of the SI unitvalues.1.4 For purposes of determining conformance of an ob
5、-served or a calculated value using this test method to relevantspecifications,test result(s)shall be rounded off“to the nearestunit”in the last right-hand digit used in expressing thespecification limit,in accordance with Practice E29.1.5 This standard does not purport to address all of thesafety c
6、oncerns,if any,associated with its use.It is theresponsibility of the user 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:2D4367 Test Method for Benzene in Hydroca
7、rbon Solventsby Gas ChromatographyE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE300 Practice for Sampling Industrial Chemicals2.2 ASTM Adjuncts:D2PP Determination of Precision and Bias Data33.Summary of Test Method3.1 A given volume of the sample
8、is introduced into a gaschromatograph equipped with two capillary columns con-nected in series by switching valve.The specimen passes firstthrough a short capillary column with a bounded nonpolarphase where the components are separated by boiling point.After octane has eluted from the first column,t
9、he componentsheavier than octane are back-flushed to vent.The octane andlighter components then pass through a second capillarycolumn with bounded polar phase where the aromatic andnonaromatic components are separated.The eluted compo-nents are detected by a flame ionization detector,and the peakare
10、as are integrated electronically.The concentration of ben-zene is calculated by a data processor using a response factordetermined by external standard technique.4.Significance and Use4.1 This test method is similar to Test Method D4367 withthe exception that capillary columns are used and intended
11、fortrace level of benzene in hydrocarbon solvents.The need fortrace benzene analysis in hydrocarbon solvents arose becauseof the increase of more stringent regulation of benzene level inthese materials.5.Apparatus5.1 ChromatographAny gas chromatographic instrumentthat has a backflush system operated
12、 by a switching valveautomatically,flame ionization detector,and can be operated atthe conditions given in Table 1.5.2 DetectorThe flame ionization detector shall have suf-ficient sensitivity to detect 0.1 vppm of benzene at a peakheight of 3 times the noise level.5.3 Columnsone 2m(6.5ft),0.53 mm in
13、side diameterfused silica capillary with 5-m thick bounded methyl silicone1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.35 on Solvents,Plasticizers,and Chemical Intermediat
14、esCurrent edition approved Dec.1,2010.Published December 2010.Originallyapproved in 1998.Last previous edition approved in 2006 as D6229 06.DOI:10.1520/D6229-06R10.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of
15、 ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from ASTM International Headquarters.Order Adjunct No.ADJD6300.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,
16、West Conshohocken,PA 19428-2959.United States1 column and one 30m(98.5ft),0.53-mm inside diameterfused silica capillary with 0.5-m thick bounded polyethyleneglycol column.5.4 Switching ValveA 6port switching valve 175C(347F)maximum temperature,housed in a separate,temperature-controlled oven,that can be activated automatically by the gaschromatograph.5.5 Sample Inlet SystemThe sample inlet system shall becapable of split injection typically at a 1:10 split ratio.NOTE2An auto injector was used in
