1、Designation:D643805(Reapproved 2015)Standard Test Method forAcetone,Methyl Acetate,and ParachlorobenzotrifluorideContent of Paints,and Coatings by Solid PhaseMicroextraction-Gas Chromatography1This standard is issued under the fixed designation D6438;the number immediately following the designation
2、indicates the year oforiginal adoption or,in the case of revision,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.Scope1.1 This test method is for the determination of
3、acetone,methyl acetate,or parachlorobenzotrifluoride(PCBTF),orcombination of any of the three,in paints and coatings,by solidphase microextraction(SPME)headspace sampling,and sub-sequent injection into a gas chromatograph.It has beenevaluated for cellulose nitrate,acrylic,and urethane solvent-borne
4、systems.The established working range of this testmethod is:acetone,28 to 90%;methyl acetate,12 to 22%;parachlorobenzotrifluoride,10 to 17%.There is no reason tobelieve that it will not work outside these ranges.A minormodification of this test method would make it suitable for theanalysis of the sa
5、me analytes in water-borne coatings(see Note1).NOTE1Water-borne paints are internally standardized and dilutedwith water followed by addition of solid sodium chloride.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 s
6、tandard 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-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 AS
7、TM Standards:2D3925 Practice for Sampling Liquid Paints and RelatedPigmented CoatingsD6133 Test Method for Acetone,p-Chlorobenzotrifluoride,Methyl Acetate or t-Butyl Acetate Content of Solvent-borne and Waterborne Paints,Coatings,Resins,and RawMaterials by Direct Injection Into a Gas ChromatographE1
8、80 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals(Withdrawn 2009)33.Terminology3.1 Abbreviations:3.1.1 PCBTFparachlorobenzotrifluoride(4-chlorobenzotrifluoride)3.1.2 MCBTFmetachlorobenzotrifluoride(3-chlorobenzotrifluoride)3.1.3
9、SPMEsolid phase microextraction3.1.4 VOCvolatile organic compound3.1.5 PEG/DVBpolyethylene glycol/divinylbenzene3.1.6 FIDflame ionization detector3.1.7 MSmass selective or mass spectral3.1.8 SIMselected ion monitoring3.1.9 GCgas chromatograph3.1.10 Srrepeatability standard deviations3.1.11 SRreprodu
10、cibility standard deviations3.1.12 rrepeatability,95%confidence limit3.1.13 Rreproducibility,95%confidence limit4.Summary of Test Method4.1 A suitable aliquot of whole solvent-borne paint isinternally standardized and diluted with dioctyl phthalate.Theheadspace of this solution is sampled with an SP
11、ME fiber,which is then thermally desorbed in the injection port of a gaschromatograph onto a suitable capillary column.Either a flameionization or mass specific detector may be used to measurepeak areas of analytes and internal standards.1This test method is under the jurisdiction of ASTM Committee
12、D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.Current edition approved June 1,2015.Published June 2015.Originallyapproved in 1999.Last previous edition approved in 2010 as D6438 05
13、(2010).DOI:10.1520/D6438-05R15.2For 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 page onthe ASTM website.3The last approved version of this
14、historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.Significance and Use5.1 In order to calculate the volatile organic content(VOC)of paints containing EPA exempt solvents,it is necessary tok
15、now the acetone,methyl acetate,or parachlorobenzotrifluo-ride content.This gas chromatographic test method provides asimple and direct way for measuring these solvents.Eachanalyte is measured with respect to a unique internal standard.For acetone,the internal standard used is acetone-d6,formethyl ac
16、etate it is methyl acetate-d3,and for PCBTF it ismetachlorobenzotrifluoride(MCBTF).These unique analyte/internal standard pairs behave very nearly as single solventswith respect to evaporation rate and adsorption rate onto acoated silica fiber(SPME)but are separable on a gas chro-matograph(GC)capillary column.The only critical analyticaltechnique required for successfully performing this test methodis the ability of an analyst to weigh a paint sample and internalstandard,corresponding to the ana