ASTM D5836-95
(Test Method)Standard Test Method for Determination of 2,4-Toluene Diisocyanate (2,4-TDI) and 2,6-Toluene Diisocyanate (2,6-TDI) in Workplace Atmospheres (1-2 PP Method)
Standard Test Method for Determination of 2,4-Toluene Diisocyanate (2,4-TDI) and 2,6-Toluene Diisocyanate (2,6-TDI) in Workplace Atmospheres (1-2 PP Method)
SCOPE
1.1 This test method describes the determination of 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI) in air samples collected from workplace atmospheres in a cassette containing a glass-fiber filter impregnated with 1-(2-pyridyl)piperazine (1-2 PP). This procedure is very effective for determining the vapor content of atmospheres. Atmospheres containing aerosols may produce low results.
1.2 This test method uses a high-performance liquid chromatograph (HPLC) equipped with a fluorescence or an ultraviolet (UV) detector (1-4).
1.3 The validated range of the test method, as written, is from 1.4 to 5.6 [mu]g of 2,4-TDI and 2,6-TDI which is equivalent to approximately 9.8 to 39 ppb for 2,4-TDI and 2,6-TDI based on a 20-L air sample. The HPLC method using an UV detector is capable of detecting 0.078 [mu]g of 2,4-TDI and 0.068 [mu]g of 2,6-TDI in a 4.0-mL solvent volume, which is equivalent to 0.55 ppb for 2,4-TDI and 0.48 ppb for 2,6-TDI based on a 20-L air sample.
1.4 The isomers of 2,4-TDI, and 2,6-TDI, can be separated utilizing a reversed phase column for the HPLC method. Because industrial applications employ an isomeric mixture of 2,4- and 2,6-TDI, the ability to achieve this separation is important.
1.5 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. See Section 9 for specific precautions.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 5836 – 95
Standard Test Method for
Determination of 2,4-Toluene Diisocyanate (2,4-TDI) and 2,6-
Toluene Diisocyanate (2,6-TDI) in Workplace Atmospheres
(1-2 PP Method)
This standard is issued under the fixed designation D 5836; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope D 1193 Specification for Reagent Water
D 1356 Terminology Relating to Sampling and Analysis of
1.1 This test method describes the determination of 2,4-
Atmospheres
toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate
D 1357 Practice for Planning the Sampling of the Ambient
(2,6-TDI) in air samples collected from workplace atmo-
Atmosphere
spheres in a cassette containing a glass-fiber filter impregnated
D 3686 Practice for Sampling Atmospheres to Collect Or-
with 1-(2-pyridyl)piperazine (1-2 PP). This procedure is very
ganic Compound Vapors (Activated Charcoal Tube Ad-
effective for determining the vapor content of atmospheres.
sorption Method)
Atmospheres containing aerosols may produce low results.
1.2 This test method uses a high-performance liquid chro-
3. Terminology
matograph (HPLC) equipped with a fluorescence or an ultra-
,
2 3 3.1 For definitions of terms used in this test method, refer to
violet (UV) detector (1-4).
Terminology D 1356.
1.3 The validated range of the test method, as written, is
from 1.4 to 5.6 μg of 2,4-TDI and 2,6-TDI which is equivalent
4. Summary of Test Method
to approximately 9.8 to 39 ppb for 2,4-TDI and 2,6-TDI based
4.1 A known volume of air is drawn through a cassette
on a 20-L air sample. The HPLC method using an UV detector
containing a glass-fiber filter impregnated with 1-(2-
is capable of detecting 0.078 μg of 2,4-TDI and 0.068 μg of
pyridyl)piperazine. The diisocyanate reacts with the secondary
2,6-TDI in a 4.0-mL solvent volume, which is equivalent to
amine to form a urea derivative.
0.55 ppb for 2,4-TDI and 0.48 ppb for 2,6-TDI based on a 20-L
4.2 The coated glass-fiber filter is extracted with acetonitrile
air sample.
(ACN) containing 10 % dimethyl sulfoxide (DMSO) and the
1.4 The isomers of 2,4-TDI, and 2,6-TDI, can be separated
extract is analyzed by HPLC. The eluent is monitored with a
utilizing a reversed phase column for the HPLC method.
fluorescence detector (240-nm excitation, 370-nm emission
Because industrial applications employ an isomeric mixture of
cutoff filter) or a UV detector (254 nm).
2,4- and 2,6-TDI, the ability to achieve this separation is
4.3 The amount of the urea derivative collected is deter-
important.
mined by comparison of sample response (peak area integra-
1.5 This standard does not purport to address all of the
tions or peak heights) to a standard calibration curve for the
safety concerns, if any, associated with its use. It is the
urea derivative.
responsibility of the user of this standard to establish appro-
4.4 The amount of diisocyanate is calculated from the
priate safety and health practices and determine the applica-
amount of urea determined in the analysis.
bility of regulatory limitations prior to use. See Section 9 for
specific precautions.
5. Significance and Use
5.1 Diisocyanates are used in the production of polyure-
2. Referenced Documents
thane foams, plastics, elastomers, surface coatings, and adhe-
2.1 ASTM Standards:
sives (5,6). It has been estimated that the production of TDI
will steadily increase during the future years.
5.2 Diisocyanates are irritants to eyes, skin, and mucous
This test method is under the jurisdiction of ASTM Committee D-22 on
Sampling and Analysis of Atmospheres and is the direct responsibility of Subcom- membrane and are respiratory sensitizers. Chronic exposure to
mittee D22.04 on Workplace Atmospheres.
low concentrations of diisocyanates produces an allergic sen-
Current edition approved Sept. 10, 1995. Published November 1995.
sitization which may progress into asthmatic bronchitis (7,8).
Validation data and a preliminary draft of this test method were provided by the
Salt Lake Technical Center of the U.S. Dept. of Labor, Occupational Safety and
Health Administration, Salt Lake City, UT.
3 4
The boldface numbers in parentheses refer to the references at the end of this Annual Book of ASTM Standards, Vol 11.01.
test method. Annual Book of ASTM Standards, Vol 11.03.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 5836
11 12
5.3 The Occupational Safety and Health Administration isorb C6 ; 5-μm Supelcosil LC-CN ; or an equivalent col-
(OSHA) has a permissible exposure limit for 2,4-TDI of 0.02 umn.
ppm or 0.14 mg/m as a ceiling limit (9). The American
7.2.3 Electronic Integrator, an electronic integrator or some
Conference of Governmental Industrial Hygienists (ACGIH)
other suitable method of determining peak areas or heights.
has a Threshold Limit Value (TLV) of 0.005 ppm or 0.036
7.2.4 Pipets and Volumetrics, various sizes of volumetric
mg/m and a short-term exposure limit (STEL) of 0.02 ppm or
pipets and flasks to prepare standards.
0.14 mg/m (10). No exposure limits have been established for
7.2.5 Vials, glass vials with a 4-mL volume and fitted with
2,6-TDI.
polytetrafluoroethylene-lined caps used for extraction of
5.4 This proposed test method has been found satisfactory
samples.
for measuring 2,4 and 2,6-TDI levels in the workplace.
8. Reagents and Materials
6. Interferences
8.1 Purity of Reagents—Reagent grade chemicals shall be
6.1 Any compound having the same retention time as the
used in all tests. It is intended that all reagents shall conform to
standards is a possible interference. Generally, chromato-
the specifications of the Committees on Analytical Reagents of
graphic conditions can be altered to resolve an interference.
the American Chemical Society, where such specifications are
6.2 Compounds that can react with an isocyanate represent
available. Other grades may be used provided it can be
a potential interference. These would include molecules con-
demonstrated that they are of sufficiently high purity to permit
taining the functional groups: amines, alcohols, anhydrides,
their use without decreasing the accuracy of the determination.
phenols, and carboxylic acids.
8.2 Purity of Water—Unless otherwise indicated, reference
6.3 Strong oxidizing agents can potentially react with the
water shall be understood to mean Type II reagent water
1-(2-pyridyl)piperazine.
conforming to Specification D 1193, HPLC grade.
6.4 Retention time data on a single column is not definitive
8.3 Acetonitrile (CH CN)—HPLC grade.
proof of chemical identity. Analysis by an alternate column
8.4 Ammonium Acetate (CH COONH )—HPLC grade.
system, ratioing of wavelength response using two wave-
3 4
lengths or types of detector, should be performed to confirm 8.5 Dimethyl Sulfoxide ((CH ) SO)—HPLC grade.
3 2
chemical identity.
8.6 Extracting Solution—A solvent mixture of acetonitrile
and dimethyl sulfoxide in the percentage of 90 and 10 (v/v),
7. Apparatus
respectively.
7.1 Sampling Equipment:
8.7 Glacial Acetic Acid (CH COOH)—Reagent grade.
7.1.1 Personal Sampling Pumps, any pump capable of
8.8 Hexane (C H )—HPLC grade.
6 14
sampling at a rate of about 1.0 L/min for 8 h.
8.9 Methylene Chloride (CH Cl )—HPLC grade.
2 2
7.1.2 Glass-Fiber Filters, 37 mm, free of organic binder,
8.10 Mobile Phase—A solvent mixture of acetonitrile (8.3)
6,7
impregnated with 1.0 mg of 1-(2-pyridyl)piperazine.
and water in the percentage of 37.5 and 62.5 (v/v), respectively.
7.1.3 Cassette, plastic holders of the three-piece personal
Add to the mobile phase enough ammonium acetate (8.4) (1.54
monitor type, that accept filters of 37-mm diameter. Number
to 7.7 g/L of solution or 0.02 to 0.1 N) to optimize the
the cassette for identification.
chromatographic resolution. Add acetic acid (8.7) to the
7.1.4 Cellulose Backup Pad, sized to fit the cassette (7.1.3).
mixture to lower the pH to 6.0 to 6.2.
7.2 Analytical Equipment:
8.11 1-(2-Pyridyl)piperazine (1-2 PP) (C H N )—Reagent
9 13 3
7.2.1 Liquid Chromatograph, a high-performance liquid
grade.
chromatograph (HPLC) equipped with a fluorescence detector
8.12 N,N8-(4-Methyl-1,3-phenylene)bis [4-(2-pyridinyl)-1-
capable of monitoring 240-nm excitation and 370-nm cutoff or
piperazinecarboxamide] (C H N O )—(2,4-TDIP).
27 32 8 2
a UV detector capable of monitoring 254-nm wavelength and
8.13 N,N8-(2-Methyl-1,3-phenylene)bis [4-(2-pyridinyl)-1-
a manual or automatic sample injector.
piperazinecarboxamide] (C H N O )—(2,6-TDIP).
7.2.2 Liquid Chromatographic Column, an HPLC stainless 27 32 8 2
steel column capable of separating the urea derivatives. Ana-
lytical columns recommended in this test method are the
following: a 25-cm by 4.6-mm inside diameter stainless steel 11
5-μm Spherisorb C6 supplied by PhaseSep, Hauppauge, NY, has been found
8 9
column packed with 10-μm Alltech C8 ; 6-μm Zorbax CN ;
satisfactory for this purpose.
5-μm Supelcosil LC-CN supplied by Supelco, Inc., Belleforte, PA has been
5-μm Zorbax TMS; 5-μm Chromegabond TMS ; 5-μm Spher-
found satisfactory for this purpose.
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
ORBO-80 filters supplied by Supelco, Inc., Bellefonte, PA have been found
listed by the American Chemical Society, see Analar Standards for Laboratory
satisfactory for this purpose.
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Isocyanate glass fiber filters supplied by Forest Biomedical, Salt Lake City, UT,
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
have been found satisfactory for this purpose.
MD.
10-μm ALLTECH C8 supplied by Alltech Associates, Deerfield, IL, has been
1-(2-Pyridyl)piperazine supplied by Aldrich Chemical, Milwaukee, WI, has
found satisfactory for this purpose.
been found satisfactory for this purpose.
6-μm ZORBAX CN and 5-μm ZORBAX TMS supplied by E.I. DuPont,
2,4-TDIP supplied by Supelco, Inc., Bellefonte, PA, is used for standardization
Wilmington, DE, have been found satisfactory for this purpose.
purposes only.
5-μm Chromegabond TMS supplied by ES Industries, Marlton, NJ, has been
2,6-TDIP supplied by Supelco, Inc., Bellefonte, PA, is used for standardization
found satisfactory for this purpose.
purposes only.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 5836
8.14 2,4-Toluene Diisocyanate (C H N O )—Reagent 12. Calibration and Standardization
9 6 2 2
grade.
12.1 Sample Pump Calibration—Calibrate the personal
8.15 2,6-Toluene Diisocyanate (C H N O )—Reagent
9 6 2 2
sampling pumps in accordance with Practice D 3686, at the
grade.
recommended flow rate with an assembled cassette between
the pump and the flow-measuring device. Calibrate the pump
9. Safety Precautions
before and after the sampling. If the postcalibration flow rate
9.1 The diisocyanates are potentially hazardous chemicals
varies more than 610 % from the precalibration flow rate,
and are extremely reactive. Avoid exposure to the diisocyanate
invalidate the sample.
standards. Sample and standard preparations should be done in
12.2 Standardization:
an efficient operating hood.
12.2.1 Prepare a stock standard solution as micrograms of
9.2 Avoid skin contact with all solvents.
TDIP per millilitre of dimethyl sulfoxide. Express the TDIP as
9.3 Wear safety glasses at all times and other laboratory
the free TDI. Multiply the amount of TDIP by the correction
protective equipment as necessary.
factor derived from the ratios of the respective molecular
10. Sampling
weights of the TDI and TDIP. The factor is 0.3479 for TDI.
12.2.2 Prepare working standards by diluting the stock
10.1 Refer to Practices D 1357 and D 3686 for general
standard with acetonitrile.
information on sampling.
12.2.3 Prepare dilution standards at the necessary concen-
10.2 Equip the worker, whose exposure is to be evaluated,
trations by diluting working standards with acetonitrile to
with a filter holder connected to a belt-supported sampling
generate a full calibration curve that brackets the sample
pump. Collect personal samples by pointing the sampler
concentrations.
downward in the breathing zone of the worker and remove the
12.2.4 Analyze by high-performance liquid chromatogra-
top for open-face sampling. Draw air through the filter at a
phy using a suitable column and the mobile phase as described
calibrated rate of approximately 1.0 L/min and collect a
in 8.10. The typical operating conditions are as follows:
maximum air sample of 15 L. Use a tripod or other support to
locate the sampler in the general room area for stationary Column temperature 25°C
Flow rate 1.0 mL/min
monitoring.
Ultraviolet 254 nm
10.3 Treat field blanks in the same manner as samples. Open
Fluorescence 240 nm, excitation
them in the environment to be sampled and immediately close 370 nm or none, emission
cutoff filter
and place with the samples to be sent to the laboratory for
Injection size 5–25 μL
analysis. Provide an unopened, unused cassette assembly as a
Analytical conditions serve as a guideline and may need to
laboratory blank. Submit at least one laboratory blank and one
be modified depending upon the specific samples, column
field blank with each set of samples.
condition, detector, and other parameters.
11. Preparation of Apparatus
12.2.5 Analyze each diisocyanate standard solution in du-
11.1 Glass-Fiber Filter—Prepare a fresh solution of 2
plicate and utilize peak area integration if possible. Peak areas
mg/mL of 1-(2-pyridyl)piperazine (8.11) in methylene chloride
should agree within 65 % per standard solution.
every time a batch of filters is to be coated. In an exhaust hood,
12.2.6 Prepare a calibration curve by plotting micrograms
set several glass-fiber filters on an appropriate holder, one that
per millilitre of diisocyanate versus peak area or peak height
will support and not contaminate the filters. Using a pipet that
values.
will deliver 0.5 mL, place 0.5 mL in the center of each filter.
12.2.7 Periodically prepare quality control samples by spik-
The liquid will just wet the filter; allow the filters to air-dry in
ing the underivatized
...
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