ASTM D7768-12
(Test Method)Standard Test Method for Speciated Organic Volatile Content of Waterborne Multi-Component Coatings by Gas Chromatography
Standard Test Method for Speciated Organic Volatile Content of Waterborne Multi-Component Coatings by Gas Chromatography
SIGNIFICANCE AND USE
5.1 In using the methods of Practice D3960 to measure the VOC content of coatings, precision tends to be poor for waterborne coatings because the VOC weight fraction is determined indirectly. The present method first identifies and then quantifies the individual VOCs directly. The total VOC weight fraction is obtained by adding the individual weight fraction values.
SCOPE
1.1 This test method is for the determination of the individual organic volatile compounds of waterborne multi-component coatings using gas chromatography (see Note 1).
1.2 The method has also been used successfully to determine the speciated volatile organic content of solvent-borne multi-component coatings. Work is continuing to develop this aspect of the method and will be added to the method at a later date.Note 1—Currently there are no methods for the direct analysis of the VOC content of waterborne multi-component coatings. The VOC content of solvent-borne multi-component coatings is determined directly by a simple weight loss determination of the mixed components (Test Method D2369).
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 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 and health practices and determine the applicability of regulatory limitations prior to use. Some specific hazards statements are given in Section 7 on Hazards.
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Standards Content (Sample)
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Designation: D7768 − 12
Standard Test Method for
Speciated Organic Volatile Content of Waterborne Multi-
Component Coatings by Gas Chromatography
This standard is issued under the fixed designation D7768; 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 D3960 PracticeforDeterminingVolatileOrganicCompound
(VOC) Content of Paints and Related Coatings
1.1 This test method is for the determination of the indi-
D4017 Test Method for Water in Paints and Paint Materials
vidual organic volatile compounds of waterborne multi-
by Karl Fischer Method
component coatings using gas chromatography (see Note 1).
D6133 Test Method for Acetone, p-Chlorobenzotrifluoride,
1.2 The method has also been used successfully to deter-
Methyl Acetate or t-Butyl Acetate Content of Solvent-
mine the speciated volatile organic content of solvent-borne
borne and Waterborne Paints, Coatings, Resins, and Raw
multi-component coatings. Work is continuing to develop this
Materials by Direct Injection Into a Gas Chromatograph
aspect of the method and will be added to the method at a later
D7358 Test Method for Water Content of Paints by Quanti-
date.
tative Calcium Hydride Reaction Test Kit
NOTE 1—Currently there are no methods for the direct analysis of the
E177 Practice for Use of the Terms Precision and Bias in
VOC content of waterborne multi-component coatings. The VOC content
ASTM Test Methods
of solvent-borne multi-component coatings is determined directly by a
E691 Practice for Conducting an Interlaboratory Study to
simple weight loss determination of the mixed components (Test Method
D2369).
Determine the Precision of a Test Method
1.3 The values stated in SI units are to be regarded as
3. Terminology
standard. No other units of measurement are included in this
3.1 Acronyms:
standard.
3.1.1 EB—2-butoxyethanol; Butyl Cellosolve, ethylene
1.4 This standard does not purport to address all of the
glycol monobutyl ether
safety concerns, if any, associated with its use. It is the
3.1.2 EGDE—ethylene glycol diethyl ether
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
3.1.3 FID—flame ionization detector
bility of regulatory limitations prior to use. Some specific
3.1.4 GC—gas chromatogaphy
hazards statements are given in Section 7 on Hazards.
3.1.5 MS—mass spectrometry
2. Referenced Documents
3.1.6 SPDE—solid phase dynamic extraction
2.1 ASTM Standards: 3.1.7 SPME—solid phase microextraction
D1475 Test Method For Density of Liquid Coatings, Inks,
4. Summary of Test Method
and Related Products
D2369 Test Method for Volatile Content of Coatings
4.1 The components are mixed, a sample of the mixture is
D3792 Test Method forWater Content of Coatings by Direct
weighed into a 20 mL headspace vial, the vial is sealed with a
Injection Into a Gas Chromatograph
crimpcap,andthemixtureisallowedtocurefor24horlonger
D3925 Practice for Sampling Liquid Paints and Related
at ambient temperature. After the initial cure, the sample is
Pigmented Coatings
heated for 30 min at 110°C.After cooling, a known quantity of
acetone containing an internal standard is added to the sealed
vial and the contents are mixed. The solution containing the
This test method is under the jurisdiction of ASTM Committee D01 on Paint
organic volatile compounds is then analyzed by gas chro-
and Related Coatings, Materials, andApplications and is the direct responsibility of
matograhpy (Note 2).
Subcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.
NOTE 2—If the cured coating contains free amines, acetone may be
Current edition approved Aug. 1, 2012. Published October 2012. DOI: 10.1520/
replaced with tetrahydrofuran (THF) as the extraction solvent. Using the
D7768–12.
2 provisions of Practice D3960, the VOC content of coatings measured in
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Butyl Cellosolve is a registered trademark of The Dow Chemical Company.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7768 − 12
g/L minus water, or other units, may be determined. Since the determi- designations Suplecowax 10, DB-Wax, HP-Wax, AT-Wax, CP-Wax 52
nation of weight percent VOC in the present method is by direct CB. Rtx-Wax, BP-20.
measurement, either the water fraction (Test Method D3792 or Test
Method D4017) or the nonvolatile fraction (Test Method D2369) may be
7. Reagents and Materials
determined indirectly in the application of Practice D3960. Since preci-
7.1 Purity of Reagents—Reagent grade chemicals shall be
sion is better for the determination of the nonvolatile content, this is the
preferred method for the indirect calculation of water content in this used in all tests. Unless otherwise indicated, all reagents shall
method. The equations for calculating regulatory VOC content when no
conform to the available specifications of the Committee on
exempt volatile compounds are present are:
Analytical Reagents of theAmerican Chemical Society. Other
grades may be used, provided it is first ascertained that the
f D
~ !
VOC P
VOC 5 (1)
reagent is of sufficiently high purity to permit its used without
1 2 @ 1 2 f 2 f D ⁄ D #
~ !~ !
NV VOC P W
or lessening the accuracy of the determination.
f D
~ ! 7.2 Carrier Gas, helium of 99.995 % or higher purity.
VOC P
VOC 5 (2)
12 @f ~D ⁄ D !#
W P W
7.3 Acetone, HPLC grade.
where:
7.4 Ethylene Glycol Diethyl Ether (EGDE), 99 mole %.
D ,f ,f , and f = coating density, nonvolatile fraction, VOC
P NV VOC w
7.5 Fluorocarbon-faced Septum Vials, 20 mL and 40 mL,
fraction, and water fraction, respectively.
Headspace Vials (20 mL), Crimp Caps, and Cripmer, Agilent
4.2 Direct GC/FID or GC/MS using solid phase microec-
Technologies part numbers: headspace vials, 5182–0837,
traction (SPME) may be used to facilitate identification of the
crimp caps, 5183–4477, and crimper, 9301–0720, or equiva-
volatile compounds present in a coating (Note 3).
lent.
NOTE 3—The analyst should consult MSDS and product data sheets for
possible information regarding solvents which may be present in a
8. Column Conditioning
particular coating.
8.1 The capillary columns should be conditioned according
to the manufacturer’s recommendation. The columns may then
5. Significance and Use
be used indefinitely without further conditioning.
5.1 In using the methods of Practice D3960 to measure the
VOC content of coatings, precision tends to be poor for
9. Coating Analysis
waterborne coatings because the VOC weight fraction is
9.1 Using a 100 mL volumetric flask, make up a concen-
determined indirectly. The present method first identifies and
trated internal standard solution containing ethylene glycol
then quantifies the individual VOCs directly. The total VOC
diethyl ether (EGDE) or other suitable internal standard in
weight fraction is obtained by adding the individual weight
acetone at a concentration of approximately 1 g per 100 mL
fraction values.
and known to the nearest 0.1 mg.
6. Apparatus
9.2 Using standard quantitative dilution techniques, dilute
the concentrated internal standard solution to give a working
6.1 Gas Chromatograph, FID Detection with Electronic
internal standard solution such that the concentration is near 1
Data Acquisition System—Any capillary gas chromatograph
mg per mL. Calculate the actual concentration. Convert the
equipped with a flame ionization detector and temperature
concentration of the working internal standard solution from
programming capability may be used. Electronic flow control,
mg/mL to mg/g by dividing by the density of acetone (0.79
which gives a constant carrier gas flow, is highly recom-
g/mL).
mended.
9.3 Determine the density of the individual components of
6.2 Standard FID Instrument Conditions:
the multi-component coating using Test Method D1475. Con-
Detector Flame ionization
vert the manufacturer’s recommended volume mix ratio to a
Columns Primary column: 30 m by 0.25 mm 5 % phenyl/95 %
methyl siloxane (PMPS) (Note 4), 1.0 µm film thickness
weight mix ratio. Using a suitable container, prepare approxi-
Confirmatory Column: 60 m by 0.25 mm Carbowax (CW),
mately 100 to 200 g of the mixture and mix using a spatula or
0.50 µm film thickness
paint shaker. Immediately after mixing, transfer approximately
Carrier Gas Helium
Flow Rate 1.0 mL per min, constant flow
100 mg of the mixture to a 20 mLheadspace vial and weigh to
Split Ratio 50 to 1
0.1 mg.Add a paper clip to the vial and then seal the vial with
Temperatures, °C
Inlet 260°C a crimp cap immediately after adding the coating mixture and
Detector 270°C
paper clip. Using an external magnet, spread the coating
Initial 50°C for 4 min
mixtureevenlyoverthebottomsurfaceofthevial.Preparetwo
Rate 20°C per min to 250°C, hold 6 min
more samples in the same way.
NOTE 4—The column designated as PMPS is commercially available
from several vendors by the following designations: DB-5, SPB-5, HP-5,
AT-5, CP Sil 8CB, Rtx-5, BP-5. The column designated as PDMS is
Reagent Chemicals, American Chemical Society Specifications, American
available by the designations DB-1, SPB-1, HP-1, AT-1, BP-1, CP Sil 5
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
CB, Rtx-1. The c
...
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