ASTM D5932-96

Standard Test Method for Determination of 2,4-Toluene Diiso cyanate (2,4-TDI) and 2,6-Toluene Diiso cyanate (2,6-TDI) in Air (with 9-(N-Methylaminomethyl) Anthracene Method) (MAMA) in the Workplace

SCOPE
1.1 This test method covers the determination of gaseous 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI) in air samples collected from workplace and ambient atmospheres.
1.2 Differential air sampling is performed with a segregating device., The gaseous fraction is collected on a glass fiber filter (GFF) impregnated with 9-(N-methylaminomethyl) anthracene (MAMA).
1.3 The analysis of the gaseous fraction is performed with a high performance liquid chromatograph (HPLC) equipped with ultraviolet (UV) and fluorescence detectors.
1.4 The analysis of the aerosol fraction is performed separately as described in Ref ().
1.5 The range of application of this test method, utilizing UV and a fluorescence detector, is validated for 0.02 to 4.2 g of monomer 2,4- and 2,6-TDI/2.0 mL of desorption solution, which corresponds to concentrations of 0.001 to 0.28 mg/m3 of TDI based on a 15-L air sample. This corresponds to 0.15 to 40 ppb(V) and brackets the established TLV value of 5 ppb(v).
1.6 The average correlation coefficient is 0.9999 and 0.9999 for the UV detector, for 2,6 and 2,4-TDI, respectively. For the fluorescence detector, the average correlation coefficient is 0.9803 and 0.9999 for 2,6 and 2,4-TDI, respectively. These values were obtained from seven standard solutions distributed along the calibration curve, each standard being injected six times, with the curve having been done twice by different operators.
1.7 The quantification limit for 2,6-TDI monomers is 0.007 μg/2 mL of desorption solution, which corresponds to 0.0005 mg/m 3 for 15-L sampled air volume for the UV detector. For the fluorescence detector, the quantification limit is 0.003 μg/2 mL of desorption solution, which correspond to 0.0002 mg/m3 for a volume of 15 L collected in air. These values are equal to ten times the standard deviation obtained from ten measurements carried out on a standard solution whose concentration of 0.02 μg/2 mL is close to the expected detection limit.
1.8 The quantification limit for 2,4-TDI monomers is 0.015 μg/2 mL of desorption solution, which corresponds to 0.001 mg/m 3 for 15-L sampled air volume for the UV detector. For the fluorescence detector, the quantification limit is 0.012 μg/2 mL of desorption solution, which corresponds to 0.0008 mg/m3 for a volume of 15 L of collected air. These values are equal to ten times the standard deviation obtained from ten measurements carried out on a standard solution whose concentration 0.02 g/2 mL is close to the expected detection limit.
1.9 2,4- and 2,6-TDI isomers can be separated using a reversed phase C18 column for HPLC. The UV and fluorescence detector response factor (RF) ratio characterize each isomer.
1.10 A field blank sampling system is used to check the possibility of contamination during the entire analytical process.
1.11 The values stated in SI units are to be regarded as the standard.
1.12 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.

General Information

• Status: Historical
• Publication Date: 09-Apr-1996
• Technical Committee: D22 - Air Quality
• Drafting Committee: D22.04 - Workplace Air Quality

Relations

• Replaced By: ASTM D5932-96(2002) - Standard Test Method for Determination of 2,4-Toluene Diiso cyanate (2,4-TDI) and 2,6-Toluene Diiso cyanate (2,6-TDI) in Air (with 9-(N-Methylaminomethyl) Anthracene Method) (MAMA) in the Workplace
• Effective Date: 10-Apr-1996

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 5932 – 96
Standard Test Method for
Determination of 2,4-Toluene Diiso cyanate (2,4-TDI)
and 2,6-Toluene Diisocyanate (2,6-TDI) in Air (with
9-(N-Methylaminomethyl) Anthracene Method) (MAMA)
in the Workplace
This standard is issued under the fixed designation D 5932; 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 fluorescence detector, the average correlation coefficient is
0.9803 and 0.9999 for 2,6 and 2,4-TDI, respectively. These
1.1 This test method covers the determination of gaseous
values were obtained from seven standard solutions distributed
2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyan-
along the calibration curve, each standard being injected six
ate (2,6-TDI) in air samples collected from workplace and
times, with the curve having been done twice by different
ambient atmospheres.
operators.
1.2 Differential air sampling is performed with a segregat-
,
2 3 1.7 The quantification limit for 2,6-TDI monomers is 0.007
ing device. The gaseous fraction is collected on a glass fiber
μg/2 mL of desorption solution, which corresponds to 0.0005
filter (GFF) impregnated with 9-(N-methylaminomethyl) an-
mg/m for 15-L sampled air volume for the UV detector. For
thracene (MAMA).
the fluorescence detector, the quantification limit is 0.003 μg/2
1.3 The analysis of the gaseous fraction is performed with a
mL of desorption solution, which correspond to 0.0002 mg/m
high performance liquid chromatograph (HPLC) equipped
for a volume of 15 L collected in air. These values are equal to
with ultraviolet (UV) and fluorescence detectors.
ten times the standard deviation obtained from ten measure-
1.4 The analysis of the aerosol fraction is performed sepa-
ments carried out on a standard solution whose concentration
rately as described in Ref (1).
of 0.02 μg/2 mL is close to the expected detection limit.
1.5 The range of application of this test method, utilizing
1.8 The quantification limit for 2,4-TDI monomers is 0.015
UV and a fluorescence detector, is validated for 0.02 to 4.2 μg
μg/2 mL of desorption solution, which corresponds to 0.001
of monomer 2,4- and 2,6-TDI/2.0 mL of desorption solution,
mg/m for 15-L sampled air volume for the UV detector. For
which corresponds to concentrations of 0.001 to 0.28 mg/m of
the fluorescence detector, the quantification limit is 0.012 μg/2
TDI based on a 15-L air sample. This corresponds to 0.15 to 40
mL of desorption solution, which corresponds to 0.0008 mg/m
ppb(V) and brackets the established TLV value of 5 ppb(v).
for a volume of 15 L of collected air. These values are equal to
1.6 The average correlation coefficient is 0.9999 and 0.9999
ten times the standard deviation obtained from ten measure-
for the UV detector, for 2,6 and 2,4-TDI, respectively. For the
ments carried out on a standard solution whose concentration
0.02 μg/2 mL is close to the expected detection limit.
1.9 2,4- and 2,6-TDI isomers can be separated using a
This test method is under the jurisdiction of ASTM Committee D-22 on
reversed phase C18 column for HPLC. The UV and fluores-
Sampling and Analysis of Atmospheresand is the direct responsibility of Subcom-
mittee D22.04 on Workplace Atmospheres. cence detector response factor (RF) ratio characterize each
Current edition approved April 10, 1996. Published June 1996.
isomer.
The sampling device for isocyanates is covered by a patent held by Jacques
1.10 A field blank sampling system is used to check the
Lesage et al, IRSST, 505 De Maisonneuve Blvd West, Montreal, Quebec, Canada.
possibility of contamination during the entire analytical pro-
Interested parties are invited to submit information regarding the identification of
acceptable alternatives to this patented item to the Committee on Standards, ASTM
cess.
Headquarters, 100 Barr Harbor Dr., PO Box C700, West Conshohocken, PA 19428.
1.11 The values stated in SI units are to be regarded as the
Your comments will receive careful consideration at a meeting of the committee
standard.
responsible, which you may attend. This sampling device is commercially available
1.12 This standard does not purport to address all of the
under license from Omega Specialty Instrument, or equivalent. Sources listed in
apparatus section of this test method.
safety concerns, if any, associated with its use. It is the
The American Society for Testing and Materials takes no position respecting
responsibility of the user of this standard to establish appro-
the validity of any patent rights asserted in connection with any item mentioned in
priate safety and health practices and determine the applica-
this standard. Users of this standard are expressly advised that determination of the
validity of any such patent rights, and the risk of infringement of such rights, are
bility of regulatory limitations prior to use.
entirely their own responsibility.
The boldface numbers in parentheses refer to the list of references at the end of
this test method.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 5932
2. Referenced Documents semi-rigid foams and adhesives.
5.2 Iso—cyanate use has been growing for the last ten years
2.1 ASTM Standards:
and the industrial need is still growing.
D 1193 Specification for Reagent Water
5.3 Diisocyanates and polyisocyanates are irritants to skin,
D 1356 Terminology Relating to Sampling and Analysis of
eyes, and mucous membranes. They are recognized to cause
Atmospheres
respiratory allergic sensitization, asthmatic bronchitis, and
D 1357 Practice for Planning the Sampling of the Ambient
acute respiratory intoxication (Refs 6-9).
Atmosphere
5.4 The American Conference of Governmental Industrial
2.2 Other Documents:
Hygienists (ACGIH) has adopted a Threshold Limit Value-
Sampling Guide for Air Contaminants in the Workplace
–Time Weighted Average (TLV—TWA) of 0.036 mg/m with
3. Terminology
a Short-Term Exposure Limit (STEL) of 0.14 mg/m for
3.1 For definitions of terms used in this test method, refer to 2,4-TDI (Ref 10). (Ref. ACGIH 1993–4). The Occupational
Terminology D 1356.
Safety and Health Administration of the U.S. Department of
Labor (OSHA) has a permissible exposure limit of 0.02
4. Summary of Test Method
ppm(V) or 0.14 mg/m of TDI as a ceiling limit (11).
4.1 A known volume of air is drawn through a segregating
5.5 Monitoring of respiratory and other problems related to
sampling device.
diisocyanates and polyisocyanates is aided through the utiliza-
4.2 Gaseous and aerosol fraction are sampled simulta-
tion of this test method, due to its sensitivity and low volume
neously with a two filter loaded cassette. The aerosol is
requirements (15 L). Its short sampling times are compatible
collected on the first filter made of polytetrafluoroethylene
with the duration of many industrial processes and its low
(PTFE), the gaseous counterpart being adsorbed on the second
detection limit also suits the concentrations often found in the
filter made of glass fiber (GFF) impregnated with MAMA.
working area.
4.3 The analysis of the monomer and oligomer in the
5.6 The segregating sampling device pertaining to this
aerosol fraction is performed separately according to the
proposed test method physically separates gas and aerosol
procedure described in Ref (1,2).
allowing isocyanate concentrations in both physical states to be
4.4 The diisocyanate present as a gas reacts with the
obtained, thus helping in the selection of ventilation systems
secondary amine function of the MAMA impregnated on the
and personal protection.
GFF to form a urea derivative (3,4).
5.7 This test method is used to measure concentrations of
2,4- and 2,6-TDI in air for workplace and ambient atmo-
spheres.
6. Interference
6.1 Any substance that can react with MAMA reagent
impregnated on the GFF can affect the sampling efficiency.
4.5 Desorption is done with dimethylformamide 67 % con-
This includes strong oxidizing agents.
taining 33 % mobile phase (70 % acetonitrile, 30 % buffer).
6.2 Any compound that has the same retention time as the
4.6 The resulting solution is analyzed by HPLC with two
TDIU derivative and gives the same UV/fluorescence detector
detectors in series: UV (254 nm) and fluorescence (254-nm
response factor ratio can cause interference. Chromatographic
exitation and 412-nm emission) Ref (5).
conditions can be changed to eliminate an interference.
4.7 2,4- and 2,6-TDI urea derivatives are separated using
6.3 A field blank double-filter sampling system is used to
reversed phase HPLC column.
check contamination during the combined sampling, transpor-
4.8 The response factor is determined by the ratio of the
tation, and sample storage process. A laboratory blank is used
concentration of the calibration solution and the area of the
to check contamination occurring during laboratory manipula-
peak obtained.
tions.
4.9 A complete calibration curve, covering the range of
application of the test method, was obtained to determine the
7. Apparatus
linearity of the method (see 1.5).
7.1 Sampling Equipment:
4.10 The amount of urea derivatives in the samples is
7.1.1 Personal Sampling Pump, capable of sampling 1.0
calculated from the response factor and the area obtained for
L/min or less for 4 h.
the sample peaks.
7.1.2 Double Filter Sampling Device, 37 mL in diameter,
4.11 The amount of diisocyanates is calculated from the
three-piece personal monitor, plastic holder loaded with a
amount of urea derivatives determined in the sample.
PTFE filter close to the mouth, followed by a glass fiber filter
impregnated with MAMA and a plastic back-up pad. The
5. Significance and Use
glass fiber filter is impregnated with an amount of MAMA in
5.1 TDI is used mostly in the preparation of rigid and
5 8
Annual Book of ASTM Standards, Vol 11.01. Sampling devices purchased from Omega Speciality Instrument, Chelmsford,
Annual Book of ASTM Standards, Vol 11.03. MA, are prepared according to the patent procedures: “Improved Sampling Device
Available from Institut de Recherche en Santé et en Sécurité du Travail du and Method for Its Use,” No. 4 961 916 (12). These have been found to be
Québec, Laboratory Division, Montreal, IRSST, 1995. satisfactory.
D 5932
the range of 0.07 to 0.25 mg. the reagent is of sufficiently high purity to permit its use
7.1.3 Flow Measuring Device. without lessening the accuracy of the determination.
7.2 Analytical Equipment: 8.2 Purity of Water—Unless otherwise indicated, water
7.2.1 Liquid Chromatograph, a high-performance liquid
shall be reagent water as defined by Type 2 of Specification
chromatograph equipped with UV (254-nm wavelength) and D 1193, HPLC grade.
fluorescence detectors (412-nm emission and 254-nm exita-
8.3 Acetonitrile (CH CN)—HPLC grade.
tion) and an automatic or manual sample injector.
8.4 Buffer—Place 30 mL of triethylamine (8.16) in water
7.2.2 Liquid Chromatographic Column, an HPLC stainless
and dilute to 1 L in a volumetric flask. Add phosphoric acid
steel column, capable of separating the urea derivatives. This
(H PO ) (8.11) to acidify to pH = 3.0. Filter the buffer under
3 4
proposed method recommends a 150- by 4.6-mm internal
vacuum with a 0.45-μm porosity filter.
diameter stainless steel column packed with 0.5-μm C18, or an
8.5 Desorption Solution—A solvent mixture of dimethylfor-
equivalent column.
mamide (8.7) and mobile phase (8.10) in the percentage of 67
7.2.3 Electronic Integrator, an electronic integrator or any
and 33 (v/v), respectively.
other effective method for determining peak areas.
8.6 Dichloromethane—Reagent grade.
7.2.4 Analytical Balance, an analytical balance capable of
8.7 Dimethylformamide—Reagent grade.
weighing to 0.001 g.
8.8 Helium (He)—“High purity.”
7.2.5 Microsyringes and Pipets, microsyringes are used in
8.9 9-(N-Methylaminomethyl) Anthracene (MAMA), (F.W.
the preparation of urea derivatives and standards. An automatic
221.31) 99 % purity.
pipet, or any equivalent method, is required for sample
8.10 Mobile Phase—A solvent mixture of acetonitrile
preparation.
(CH CN) (8.3) and buffer (8.4) in the percentage of 70 and 30
7.2.6 pH Meter, a pH meter or any equivalent device
(v/v), respectively, suitably degased.
capable of assaying a pH range between 2.5 and 7.
8.11 Phosphoric Acid (H PO )—Reagent grade.
3 4
7.2.7 Specialized Flasks, three-necked flask and an addi-
8.12 2,4-Toluene Diisocyanate (2,4-TDI) —(F.W. 174.2)
tional flask for the synthesis of the TDIU standard.
97 % purity.
7.2.8 Magnetic Stirrer, a magnetic stirrer or any other
8.13 2,6-Toluene Diisocyanate (2,6-TDI) —(F.W. 174.2)
equivalent method.
97 % purity.
7.2.9 Ointment Jars, 30 mL, ointment jars and lid, capable
8.14 2,4-Toluene Diisocyanate 9-(N-Methylaminomethyl)
of receiving 37-mm filters, used for desorption of samples.
Anthracene Derivative (2,4-TDIU).
7.2.10 Reciprocating Shaker, a reciprocating shaker or any
8.14.1 Add 320 μL of 2,4-TDI (8.13) (2 mmoles) to dichlo-
other equivalent device.
romethane (8.6) and dilute to 25 mL in a volumetric flask.
7.2.11 Vacuum Filtration System, vacuum filtration system
Place the 2,4-TDI solution in an additional flask.
with 0.45-μm porosity nylon filters or any equivalent method
8.14.2 Dilute approximately 1.3 g (6 mmoles) of 9-(N-
to degas the mobile phase.
methylaminomethyl) anthracene (MAMA) (8.9) in 50 mL of
7.2.12 Syringe Operated Filter Unit, syringes with polyvi-
dichloromethane (8.6). Place the MAMA solution in a three-
nylidene fluoride 0.45-μm porosity filter unit, or any equiva-
necked flask.
lent method.
8.14.3 Add the TDI (8.13) drop by drop at a temperature of
7.2.13 Injection Vials, 1.5-mL vials with PTFE-coated sep-
25°C to the MAMA solution 8.14.2), stirring continuously for
tums for injection.
60 to 90 min.
7.2.14 Bottle, amber-colored bottle with cap and PTFE-
8.14.4 Cool the resulting solution on crushed ice.
coated septum for conservation of stock and standard solutions
8.14.5 Filter on a medium speed ashless filter paper or any
of 2,4- and 2,6-TDIU or any equivalent method.
equivalent device.
8. Reagents and Materials 8.14.6 Dissolve the precipitate in hot dichloromethane (8.6).
Place in an ice bath to recrystallize and filter as in 8.14.5.
8.1 Purity of Reagents—Reagent grade chemicals shall be
8.14.7 The compound has a melting point of 270°C.
used in all tests. All reagents shall conform to the specifications
8.14.8 Confirm that the urea derivative with the mass
of the Committee on Analytical Reagents o
...