ASTM D7768-12(2018)

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: D7768 − 12 (Reapproved 2018)
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 D2369 Test Method for Volatile Content of Coatings
D3792 Test Method forWater Content of Coatings by Direct
1.1 This test method is for the determination of the indi-
Injection Into a Gas Chromatograph
vidual organic volatile compounds of waterborne multi-
D3925 Practice for Sampling Liquid Paints and Related
component coatings using gas chromatography (see Note 1).
Pigmented Coatings
1.2 The method has also been used successfully to deter-
D3960 PracticeforDeterminingVolatileOrganicCompound
mine the speciated volatile organic content of solvent-borne
(VOC) Content of Paints and Related Coatings
multi-component coatings. Work is continuing to develop this
D4017 Test Method for Water in Paints and Paint Materials
aspect of the method and will be added to the method at a later
by Karl Fischer Method
date.
D6133 Test Method for Acetone, p-Chlorobenzotrifluoride,
NOTE 1—Currently there are no methods for the direct analysis of the
Methyl Acetate or t-Butyl Acetate Content of Solvent-
VOC content of waterborne multi-component coatings. The VOC content
borne and Waterborne Paints, Coatings, Resins, and Raw
of solvent-borne multi-component coatings is determined directly by a
Materials by Direct Injection Into a Gas Chromatograph
simple weight loss determination of the mixed components (Test Method
D2369).
D7358 Test Method for Water Content of Paints by Quanti-
tative Calcium Hydride Reaction Test Kit
1.3 The values stated in SI units are to be regarded as
E177 Practice for Use of the Terms Precision and Bias in
standard. No other units of measurement are included in this
ASTM Test Methods
standard.
E691 Practice for Conducting an Interlaboratory Study to
1.4 This standard does not purport to address all of the
Determine the Precision of a Test Method
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3. Terminology
priate safety, health, and environmental practices and deter-
3.1 Acronyms:
mine the applicability of regulatory limitations prior to use.
3.1.1 EB—2-butoxyethanol; Butyl Cellosolve, ethylene
1.5 This international standard was developed in accor-
glycol monobutyl ether
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
3.1.2 EGDE—ethylene glycol diethyl ether
Development of International Standards, Guides and Recom-
3.1.3 FID—flame ionization detector
mendations issued by the World Trade Organization Technical
3.1.4 GC—gas chromatogaphy
Barriers to Trade (TBT) Committee.
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,
and Related Products
4. Summary of Test Method
4.1 The components are mixed, a sample of the mixture is
This test method is under the jurisdiction of ASTM Committee D01 on Paint
weighed into a 20 mL headspace vial, the vial is sealed with a
and Related Coatings, Materials, andApplications and is the direct responsibility of
crimpcap,andthemixtureisallowedtocurefor24horlonger
Subcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.
at ambient temperature. After the initial cure, the sample is
Current edition approved June 1, 2018. Published June 2018. Originally
approved in 2012. Last previous edition approved in 2012 as D7768 – 12. DOI: heated for 30 min at 110°C.After cooling, a known quantity of
10.1520/D7768-12R18.
acetone containing an internal standard is added to the sealed
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 (2018)
vial and the contents are mixed. The solution containing the
Rate 20°C per min to 250°C, hold 6 min
organic volatile compounds is then analyzed by gas chro-
NOTE 4—The column designated as PMPS is commercially available
matograhpy (Note 2).
from several vendors by the following designations: DB-5, SPB-5, HP-5,
NOTE 2—If the cured coating contains free amines, acetone may be
AT-5, CP Sil 8CB, Rtx-5, BP-5. The column designated as PDMS is
replaced with tetrahydrofuran (THF) as the extraction solvent. Using the
available by the designations DB-1, SPB-1, HP-1, AT-1, BP-1, CP Sil 5
provisions of Practice D3960, the VOC content of coatings measured in
CB, Rtx-1. The column designated as Carbowax is available by the
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 SDS 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
Temperatures, °C
Inlet 260°C
Reagent Chemicals, American Chemical Society Specifications, American
Detector 270°C
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
Initial 50°C for 4
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