ASTM D6438-05(2022)
(Test Method)Standard Test Method for Acetone, Methyl Acetate, and Parachlorobenzotrifluoride Content of Paints, and Coatings by Solid Phase Microextraction-Gas Chromatography
Standard Test Method for Acetone, Methyl Acetate, and Parachlorobenzotrifluoride Content of Paints, and Coatings by Solid Phase Microextraction-Gas Chromatography
SIGNIFICANCE AND USE
5.1 In order to calculate the volatile organic content (VOC) of paints containing EPA exempt solvents, it is necessary to know the acetone, methyl acetate, or parachlorobenzotrifluoride content. This gas chromatographic test method provides a simple and direct way for measuring these solvents. Each analyte is measured with respect to a unique internal standard. For acetone, the internal standard used is acetone-d6, for methyl acetate it is methyl acetate-d3, and for PCBTF it is metachlorobenzotrifluoride (MCBTF). These unique analyte/internal standard pairs behave very nearly as single solvents with respect to evaporation rate and adsorption rate onto a coated silica fiber (SPME) but are separable on a gas chromatograph (GC) capillary column. The only critical analytical technique required for successfully performing this test method is the ability of an analyst to weigh a paint sample and internal standard, corresponding to the analyte of interest, into a septum capped vial. After weighing, solvent evaporation has no effect on the final value of the determination. Since whole paint is not injected into the gas chromatograph, the analytical system is never compromised.
SCOPE
1.1 This test method is for the determination of acetone, methyl acetate, or parachlorobenzotrifluoride (PCBTF), or combination of any of the three, in paints and coatings, by solid phase microextraction (SPME) headspace sampling, and subsequent injection into a gas chromatograph. It has been evaluated for cellulose nitrate, acrylic, and urethane solvent-borne systems. The established working range of this test method is: acetone, 28 to 90 %; methyl acetate, 12 to 22 %; parachlorobenzotrifluoride, 10 to 17 %. There is no reason to believe that it will not work outside these ranges. A minor modification of this test method would make it suitable for the analysis of the same analytes in water-borne coatings (see Note 1).
Note 1: Water-borne paints are internally standardized and diluted with water followed by addition of solid sodium chloride.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D6438 −05 (Reapproved 2022)
Standard Test Method for
Acetone, Methyl Acetate, and Parachlorobenzotrifluoride
Content of Paints, and Coatings by Solid Phase
Microextraction-Gas Chromatography
This standard is issued under the fixed designation D6438; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
1.1 This test method is for the determination of acetone, 2.1 ASTM Standards:
methyl acetate, or parachlorobenzotrifluoride (PCBTF), or D3925 Practice for Sampling Liquid Paints and Related
combinationofanyofthethree,inpaintsandcoatings,bysolid Pigmented Coatings
phase microextraction (SPME) headspace sampling, and sub- D6133 Test Method for Acetone, p-Chlorobenzotrifluoride,
sequent injection into a gas chromatograph. It has been Methyl Acetate or t-Butyl Acetate Content of Solvent-
evaluated for cellulose nitrate, acrylic, and urethane solvent- borne and Waterborne Paints, Coatings, Resins, and Raw
borne systems. The established working range of this test Materials by Direct Injection Into a Gas Chromatograph
method is: acetone, 28 to 90 %; methyl acetate, 12 to 22 %; E180 Practice for Determining the Precision of ASTM
parachlorobenzotrifluoride, 10 to 17 %. There is no reason to Methods for Analysis and Testing of Industrial and Spe-
believe that it will not work outside these ranges. A minor cialty Chemicals (Withdrawn 2009)
modification of this test method would make it suitable for the
3. Terminology
analysisofthesameanalytesinwater-bornecoatings(seeNote
1).
3.1 Abbreviations:
3.1.1 PCBTF—parachlorobenzotrifluoride
NOTE 1—Water-borne paints are internally standardized and diluted
(4-chlorobenzotrifluoride)
with water followed by addition of solid sodium chloride.
3.1.2 MCBTF—metachlorobenzotrifluoride
1.2 The values stated in SI units are to be regarded as
(3-chlorobenzotrifluoride)
standard. No other units of measurement are included in this
standard.
3.1.3 SPME—solid phase microextraction
1.3 This standard does not purport to address all of the
3.1.4 VOC—volatile organic compound
safety concerns, if any, associated with its use. It is the
3.1.5 PEG/DVB—polyethylene glycol/divinylbenzene
responsibility of the user of this standard to establish appro-
3.1.6 FID—flame ionization detector
priate safety, health, and environmental practices and deter-
3.1.7 MS—mass selective or mass spectral
mine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accor-
3.1.8 SIM—selected ion monitoring
dance with internationally recognized principles on standard-
3.1.9 GC—gas chromatograph
ization established in the Decision on Principles for the
3.1.10 Sr—repeatability standard deviations
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical 3.1.11 SR—reproducibility standard deviations
Barriers to Trade (TBT) Committee.
3.1.12 r—repeatability, 95 % confidence limit
1 2
This test method is under the jurisdiction of ASTM Committee D01 on Paint For referenced ASTM standards, visit the ASTM website, www.astm.org, or
and Related Coatings, Materials, andApplications and is the direct responsibility of contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Subcommittee D01.21 on Chemical Analysis of Paints and Paint Materials. Standards volume information, refer to the standard’s Document Summary page on
CurrenteditionapprovedJune1,2022.PublishedJuly2022.Originallyapproved the ASTM website.
in 1999. Last previous edition approved in 2015 as D6438 – 05 (2015). DOI: The last approved version of this historical standard is referenced on
10.1520/D6438-05R22. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6438 − 05 (2022)
3.1.13 R—reproducibility, 95 % confidence limit 6.2 Gas Chromatograph, FID Detection—Any capillary gas
chromatograph equipped with a flame ionization detector may
4. Summary of Test Method
be used. Temperature programming capability is desirable, but
4.1 A suitable aliquot of whole solvent-borne paint is
isothermal operations may be utilized.
internally standardized and diluted with dioctyl phthalate. The
6.2.1 For FID instrument conditions, see Table 1.
headspace of this solution is sampled with an SPME fiber,
6.2.2 Inlet Liner, 0.75-mm should be placed in the injection
which is then thermally desorbed in the injection port of a gas
port.
chromatograph onto a suitable capillary column. Either a flame
6.2.3 Integrator—Any electronic integrator that can accu-
ionization or mass specific detector may be used to measure
rately quantify a gas chromatographic peak area is acceptable.
peak areas of analytes and internal standards.
6.3 Gas Chromatograph, Mass Selective (MS) Detection—
5. Significance and Use
Any capillary gas chromatograph equipped with a mass selec-
tive detector may be used. The detector must be capable of
5.1 In order to calculate the volatile organic content (VOC)
measuring in the selected ion monitoring (SIM) mode at dwell
of paints containing EPA exempt solvents, it is necessary to
times of 100 milliseconds or less.
know the acetone, methyl acetate, or parachlorobenzotrifluo-
6.3.1 For MS instrument conditions, see Table 2.
ride content. This gas chromatographic test method provides a
6.3.2 Inlet liner, 0.75-mm, should be placed in the injection
simple and direct way for measuring these solvents. Each
port.
analyte is measured with respect to a unique internal standard.
6.3.3 The instrument should have a software data system to
For acetone, the internal standard used is acetone-d6, for
allow extraction and integration of the SIM ions.
methyl acetate it is methyl acetate-d3, and for PCBTF it is
metachlorobenzotrifluoride (MCBTF). These unique analyte/
internal standard pairs behave very nearly as single solvents 7. Column and Fiber Conditioning
with respect to evaporation rate and adsorption rate onto a
7.1 Either or both capillary columns should be conditioned
coated silica fiber (SPME) but are separable on a gas chro-
according to the manufacturer’s recommendation. The col-
matograph (GC) capillary column. The only critical analytical
umns may then be used indefinitely without further condition-
techniquerequiredforsuccessfullyperformingthistestmethod
ing.
is the ability of an analyst to weigh a paint sample and internal
7.2 TheSPMEfibershouldbeconditionedandusedaccord-
standard,correspondingtotheanalyteofinterest,intoaseptum
ing to the manufacturer’s recommendation.
capped vial. After weighing, solvent evaporation has no effect
onthefinalvalueofthedetermination.Sincewholepaintisnot
7.3 The SPME fiber should be inserted into a 260 °C
injected into the gas chromatograph, the analytical system is
injection port for 30 s prior to daily use.
never compromised.
8. Reagents and Materials
6. Apparatus
8.1 Purity of Reagents—Reagent grade chemicals shall be
6.1 Manual SPME Holder, fitted with partially crosslinked
used in all tests. Unless otherwise indicated, it is intended that
polyethylene glycol/divinylbenzene (PEG/DVB) fiber
all reagents shall conform to the specifications of the Commit-
assembly, 65-µm film thickness.
tee onAnalytical Reagents of theAmerican Chemical Society,
The sole source of supply of the manual holder and fibers known to the
committee at this time is Supelco Company, Supelco Park, Bellefonte, PA
16823-0048. If you are aware of alternative suppliers, please provide this informa-
tion to ASTM International Headquarters. Your comments will receive careful
TABLE 2 MS Instrument Conditions
consideration at a meeting of the responsible technical committee, which you may
attend.
Detector: Electron ionization or mass selective
Detection Mode: Selected ion monitoring (SIM) of ions m/e 58, 64,
74, 77, and 180
TABLE 1 FID Instrument Conditions
Dwell Time: 100 milliseconds or less
Detector: Flame ionization Solvent Delay: 0.0 min
Column: 60m×0.25mm100%polyethylene glycol, 0.5-µm Column: 25m×0.20mm5% phenyl/95 % methyl
film thickness polydimethylsiloxane
Carrier Gas: Helium Carrier Gas: Helium
Flow Rage: 1.0 mL per minute (20 cm per second) Flow Rate: 1.0 mL per minute (20 cm per second)
Split Ratio: 200 to 1 Split Ratio: 200 to 1
A A
Fiber desorption time: 5 to 6 s Fiber desorption time: 5 to 6 s
Temperature, °C Temperatures, °C
Inlet 260° Inlet 260°
Detector 270° Detector 280°
Initial 35° for 12 min Initial 40° for 2 min
Rate 1 30° per minute to 100°, hold 10 min Rate 1 10° per minute to 90°, hold 1 min
Rate 2 30° per minute to 240°, hold 2 min Rate 2 40° per minute to 240°, hold 1 min
A A
If the fiber desorption is carried out longer than 5 or 6 s, the acetone peaks If the fiber desorption is carried out longer than 5 or 6 s, the acetone peaks
exhibit tailing. A 5 to 6-s desorption time transfers 98 to 99 % of the analytes to the exhibit tailing. A 5 to 6-s desorption time transfers 98 to 99 % of the analytes to the
capillary column. The fiber may be cleaned by inserting it into the GC inlet for 15 capillary column. The fiber may be cleaned by inserting it into the GC inlet for 15
s after analytes of interest have eluted. s after analytes of interest have eluted.
D6438 − 05 (2022)
where such specifications are available. Other grades may be 9.8 If using the GC/FID procedure measure the peak areas
used, provided it is first ascertained that the reagent is of of the three analytes and three standards by integration (see
sufficiently high purity to permit its use without lessening the Note 5). Curve fitting software for measuring peak areas is
accuracy of the determination. advantageous in some instances.
8.2 Carrier Gas—Helium of 99.995 % or higher purity. NOTE 5—The approximate retention times in minutes are as follows:
acetone-d6, 10.35; acetone, 10.56; methyl acetate-d3, 11.06; methyl
8.3 Aceto
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.