| Safety and Health Topics > Sampling and Analytical Methods > Index |
Printing Instructions
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1,6-Hexanediol Diacrylate
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| Method no.: |
PV2133 |
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| Control no.: |
T-PV2133-01-0403-M |
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| Target Concentration: |
1 mg/m3 (AIHA Workplace Environmental Exposure Level (WEEL)) |
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| Procedure: |
Samples
are collected by drawing a known volume of air through glass sampling tubes
containing Chromosorb 106. Samples are
extracted with 99:1 carbon disulfide:N,N-dimethylformamide and analyzed
by GC using a flame ionization detector. |
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| Recommended sampling time and sampling rate: |
240 min at 0.2 L/min (48 L) |
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| Reliable quantitation limit: |
43
µg/m3 |
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| Status of method: |
Partially
evaluated method. This method has been subjected to established evaluation
procedures of the Methods Development Team and is presented for information and
trial use. |
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| March 2004 |
Mary Eide |
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Methods Development Team
Industrial Hygiene Chemistry Division
OSHA Salt Lake Technical
Center
Sandy UT 84070-6406
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1. General Discussion
1.1 Background
1.1.1 History
Air samples
collected using Chromosorb 106 tubes were received at OSHA SLTC with requested
analysis for 1,6-hexanediol diacrylate. This partially-validated work was performed because SLTC had no sampling
and analytical method for 1,6-hexanediol diacrylate.
The result of
a preliminary extraction efficiency study for 1,6-hexanediol diacrylate
extracted from dry Chromosorb 106 with carbon disulfide was 99% recovery. The test was repeated with wet Chromosorb 106
and the recovery was initially the same, but then decreased to 85.2% when the
samples were allowed to stand. The
source of dry Chromosorb 106 was sampling tubes as received from SKC Inc. The source of wet Chromosorb 106 was dry
Chromosorb 106 sampling tubes which had clean, humid air drawn through them. The extraction solvent was changed from pure
carbon disulfide to 99:1 carbon disulfide:N,N-dimethylformamide
and the wet Chromosorb 106 extraction efficiency test was repeated. The results of this test showed no decrease
in recovery, therefore, the 99:1 carbon disulfide:N,N-dimethylformamide extraction solvent was selected for use in
this work. The extraction efficiency was
98.9% using the 99:1 carbon disulfide:N,N-dimethylformamide
extraction solvent.
1,6-Hexanediol
diacrylate was found to be well retained on Chromosorb 106, with a retention
efficiency recovery of 98.7% and the storage stability recovery of 97.3% on day
14 of ambient storage.
1.1.2 Toxic
effects (This section is for
information only and should not be taken as the basis of OSHA policy.)1,2
1,6-Hexanediol diacrylate is a
contact irritant severely affecting the skin, eyes, and respiratory
system. It is moderately toxic by skin
contact and may cause sensitization.
1.1.3 Workplace exposure3
1,6-Hexanediol diacrylate is used as a cross-linking agent in UV curing, inks and coatings.
1.1.4 Physical
properties and other descriptive information4,5
| CAS number: |
13048-33-4 |
| synonyms: |
acrylic
acid hexamethylene ester; hexaneglycol diacrylate; Kayard HDDA; Photomer 4017;
propenoic acid, 1,6-hexanediol ester; 2-propenoic acid, 1,6-hexanediyl ester;
Setalux UV 2243; Viscoat 230 |
| IMIS:6 |
H128 |
| RTECS: |
AT1430000 |
| molecular weight: |
226.3 |
| density (g/mL): |
1.01 |
| melting point: |
5 °C |
| boiling point: |
107 °C |
| appearance: |
clear liquid |
| flash point: |
132 °C (270 °F)
(Cleveland open cup) |
| odor: |
mild ester-like |
| molecular
formula: |
C12H10O4 |
| solubility: |
acetone,
alcohol, benzene, and carbon tetrachloride |
| autoignition
temperature: |
235 °C (455 °F) |
structural formula:
This
method was evaluated according to the OSHA SLTC "Evaluation Guidelines for Air
Sampling Methods Utilizing Chromatographic Analysis"7.The Guidelines define analytical parameters,
specify required laboratory tests, statistical calculations and acceptance
criteria. The analyte air concentrations
throughout this method are based on the recommended sampling and analytical
parameters.
1.2 Detection
limit of the overall procedure (DLOP) and reliable quantitation limit (RQL)
The
DLOP is measured as mass per sample and expressed as equivalent air
concentration, based on the recommended sampling parameters. Ten samplers were spiked with equal
descending increments of analyte, such that the highest sampler loading was 8.08
µg of 1,6-hexanediol diacrylate. This is the amount spiked on a sampler that
would produce a peak at least 10 times the response for a sample blank. These spiked samplers were analyzed with the
recommended analytical parameters, and the data obtained used to calculate the required
parameters (standard error of estimate and slope) for the calculation of the
DLOP. The slope was 1007 and the SEE was
234. The RQL is considered the lower
limit for precise quantitative measurements. It is determined from the regression line parameters obtained for the
calculation of the DLOP, providing 75% to 125% of the analyte is recovered. The DLOP and RQL were 0.70 µg and 2.32 µg, respectively.
The
recovery at the RQL was 98.2%.
Table 1.2
Detection Limit of the Overall Procedure for 1,6-Hexanediol Diacrylate
|
mass per sample
(µg) |
area counts
(µV-s) |
|
| 0.00 |
0 |
| 0.81 |
721 |
| 1.62 |
1230 |
| 2.42 |
1863 |
| 3.23 |
2592 |
| 4.04 |
3586 |
| 4.85 |
4360 |
| 5.66 |
5341 |
| 6.46 |
6143 |
| 7.27 |
7105 |
| 8.08 |
8089 |
|
Figure 1.2.1
Plot of data to determine the DLOP/RQL for 1,6-hexanediol
diacrylate. (y = 1007x - 337) |
Below is a chromatogram of 1,6-Hexanediol near the RQL.
The recovery was 89.2% at this level.
Figure 1.2.2
Chromatogram of 1,6-hexanediol diacrylate peak
near the RQL.
(Key: (1) 1, 6-hexanediol diacrylate)
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2. Sampling Procedure
All safety
practices that apply to the work area being sampled should be followed. The sampling equipment should be attached to
the worker in such a manner that it will not interfere with work performance or
safety.
2.1 Apparatus
2.1.1 Samples are collected using a personal
sampling pump calibrated, with the sampling device attached, to within ±5% of the recommended flow rate.
2.1.2 Samples
are collected with 7-cm × 4-mm i.d. × 7-mm o.d. glass sampling tubes packed with two
sections (100/50 mg) of Chromosorb 106. The sections are held in place with foam plugs and with a glass wool
plug at the front. For this evaluation,
commercially prepared sampling tubes were purchased from SKC, Inc. (Catalog no.
226-110, lot 2573).
2.2 Reagents
None required.
2.3 Technique
2.3.1 Immediately
before sampling, break off the ends of the flame-sealed tube to provide an
opening approximately half the internal diameter of the tube. Wear eye protection when breaking the
tube. Use tube holders to minimize the
hazard of broken glass. All tubes should
be from the same lot.
2.3.2 The
smaller section of the adsorbent tube is used as a back-up and is positioned
nearest the sampling pump. Attach the
tube holder to the sampling pump so that the adsorbent tube is in an
approximately vertical position with the inlet facing down during
sampling. Position the sampling pump,
tube holder and tubing so they do not impede work performance or safety.
2.3.3 Draw
the air to be sampled directly into the inlet of the tube holder. The air being sampled is not to be passed
through any hose or tubing before entering the sampling tube.
2.3.4 After
sampling for the appropriate time, remove the adsorbent tube and seal it with
plastic end caps. Seal each sample
end-to-end with an OSHA-21 form as soon as possible.
2.3.5 Submit
at least one blank sample with each set of samples. Handle the blank sample in the same manner as
the other samples except draw no air through it.
2.3.6 Record
sample air volumes (liters), sampling time (minutes), and sampling rate (L/min)
for each sample, along with any potential interference on the OSHA-91A form.
2.3.7 Submit
the samples to the laboratory for analysis as soon as possible after
sampling. If delay is unavoidable, store
the samples at refrigerator temperature. Ship any bulk samples separate from the air samples.
2.4 Extraction efficiency
The
extraction efficiency was determined by spiking the front sections of
Chromosorb 106 tubes with 1, 6-hexanediol diacrylate at 0.1 to 2 times the
target concentration, based on a 48-L air volume, for a loading of 4.85 to 97.0
µg/sample. These samples were stored overnight at
ambient temperature and then extracted with 1 mL of extracting solvent on a
shaker for 30 minutes, and analyzed by GC-FID. The mean extraction efficiency over the studied range was 98.9%. The wet
extraction efficiency was determined at 1 times the target concentration by
liquid spiking the analyte onto Chromsorb 106 tubes which had 48-L humid air
(absolute humidity of 15.9 mg/L of water, about 80% relative humidity at 22.2 °C) drawn through them immediately before spiking.
The mean recovery for the wet samples was 98.7%.
Table 2.4
Extraction Efficiency (%) of 1,6-Hexanediol Diacrylate |
|
level
|
sample number
|
mean
|
|
x target
concn |
µg per
Sample |
1 |
2 |
3 |
4 |
5 |
6 |
|
|
| 0.1 |
4.85 |
98.7 |
99.3 |
97.9 |
97.6 |
99.0 |
99.1 |
98.6 |
| 0.5 |
24.3 |
99.8 |
99.9 |
99.4 |
98.7 |
99.9 |
99.7 |
99.6 |
| 1.0 |
48.5 |
98.9 |
99.0 |
98.3 |
98.0 |
98.5 |
98.2 |
98.5 |
| 1.5 |
72.7 |
99.0 |
97.9 |
98.7 |
98.3 |
98.7 |
98.9 |
98.6 |
| 2.0 |
97.0 |
98.7 |
99.2 |
99.0 |
98.9 |
99.1 |
99.2 |
99.0 |
|
|
| 1.0
(wet) |
48.5 |
97.9 |
98.7 |
98.9 |
98.8 |
99.3 |
98.3 |
98.7 |
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2.5 Retention efficiency
Six
Chromosorb 106 tubes were spiked with 97.0 µg (2.02 mg/m3) of 1,6-hexanediol diacrylate in the
front sections, and allowed to equilibrate for 4 h. The tubes had 48-L humid air (absolute
humidity of 15.9 mg/L of water, about 80% relative humidity at 22.2 °C) pulled through them at 0.2
L/min. The samples were extracted and
analyzed. The mean recovery was 98.7%. There was no analyte found on the back-up section of any of the tubes.
Table 2.5
Retention Efficiency (%) of
1,6-Hexanediol Diacrylate |
|
section
|
sample number
|
mean
|
| |
1 |
2 |
3 |
4 |
5 |
6 |
|
|
| front of spiked tube |
99.0 |
98.7 |
99.2 |
98.8 |
97.9 |
98.3 |
98.7 |
| rear of spiked tube |
0.0 |
0.0 |
0.0 |
0.0 |
0.0 |
0.0 |
0.0 |
| total |
99.0 |
98.7 |
99.2 |
98.8 |
97.9 |
98.3 |
98.7 |
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2.6 Sample storage
Fifteen
Chromosorb 106 tubes were each spiked with 48.5 µg (1.01 mg/m3) of 1,6-hexanediol diacrylate.
They were allowed to equilibrate for 6h, then
48 L of air, with an absolute humidity of 15.7 milligrams of water per liter of
air (about 80% relative humidity at 23 °C), drawn through them. Three samples were analyzed immediately, and the rest were sealed.
Six samples were stored at room temperature
(23 °C), while the other six samples were stored at refrigerated temperature (4 °C).
Three samples from each set of storage
samples were analyzed after 7 days of
storage and the remaining three from each set after 14 days. The amounts recovered indicate good storage
stability for the time period studied.
Table 2.6
Storage Test for
1,6-Hexanediol Diacrylate |
|
| time (days) |
ambient storage recovery (%) |
refrigerated storage recovery (%) |
|
| 0 |
98.5 |
99.0 |
99.4 |
|
|
|
| 4 |
98.1 |
98.6 |
97.8 |
98.8 |
99.1 |
98.2 |
| 14 |
96.9 |
98.0 |
97.0 |
98.2 |
98.9 |
97.8 |
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2.7 Recommended air volume and sampling rate
Based
on the data collected in this evaluation, 48-L air samples should be collected
at a sampling rate of 0.2 L/min for 240 minutes.
2.8 Interferences (sampling)
2.8.1 There are no known compounds which will
severely interfere with the collection of 1,6-hexanediol diacrylate.
2.8.2 Suspected interferences should be reported to the laboratory with submitted samples.
3. Analytical Procedure
Adhere
to the rules set down in your Chemical Hygiene Plan. Avoid skin contact and inhalation of all
chemicals and review all appropriate MSDSs.
3.1 Apparatus
3.1.1 A gas
chromatograph equipped with an FID detector. For this evaluation, an Agilent 6890 GC was used.
3.1.2 A GC
column capable of separating 1,6-hexanediol diacrylate from the extraction
solvent, internal standard, and any potential interferences. A 60-m × 0.32-mm i.d. capillary column coated
with DB-1 with a 1.0-µm df (J&W Scientific, Folsom, CA) was used in this
evaluation.
3.1.3 An
electronic integrator or some other suitable means of measuring peak
areas. A Waters Millennium32
Data System and an Agilent
3396
integrator were used in this evaluation.
3.1.4 Glass
vials with poly(tetrafluoroethylene)-lined caps. For this evaluation 2-mL vials were used.
3.1.5 A dispenser capable of delivering 1.0 mL of extraction
solvent to prepare standards and samples. If a dispenser is not available, a 1.0-mL volumetric pipet may be used.
3.1.6 Volumetric
flasks – 10-mL and other convenient sizes for preparing standards.
3.1.7 Calibrated
10-µL
syringe for preparing standards.
3.1.8 A
shaker or rotator to agitate samples during extraction. An Eberbach mechanical shaker was used in
this evaluation.
3.2 Reagents
3.2.1 1,6-Hexanediol
diacrylate, technical grade. Aldrich 80%
(lot 16304HA) was used in this evaluation.
3.2.2 Carbon
disulfide, Reagent grade. EM Science Omni-Solv® 99.99% (lot 43279343), was used in this
evaluation.
3.2.3 N,N-Dimethylformamide, anhydrous. Aldrich 99.8% (lot 04643LA) was used in this
evaluation.
3.2.4 p-Cymene, reagent grade. Aldrich 99% (lot 11703TR) was used in this
evaluation.
3.2.5 The
extraction solvent was a solution of 99:1 carbon disulfide:DMF with 0.25 µL/mL of p-cymene
as internal standard.
3.3 Standard preparation
3.3.1 Prepare
at least two stock analytical standards by injecting microliter quantities of 1,6-hexanediol
diacrylate from a microliter syringe into volumetric flasks containing the extraction
solvent. Working analytical standards
are prepared by serial dilutions of the stock standard with the extraction
solvent. A stock standard of 6 µL/10 mL (0.6 µL/mL) is equivalent to 485 µg/mL, based on the density and the purity of 80%.
A 1:10 dilution of this stock standard is 48.5 µg/mL, which is equivalent to 1.01 mg/m3
based on a 48-L air volume.
3.3.2 Bracket
sample concentrations with standard concentrations. If sample concentrations are higher than the
concentration range of prepared standards, either analyze higher standards, or
dilute the sample. Diluted samples
should be prepared with the extracting solvent to obtain a concentration within
the existing standard range. The range
of standards used in this study was from 1 to 121 µg/mL. A
check standard from a second source should be prepared to check the
calibration.
3.4 Sample preparation
3.4.1 Remove
the plastic end caps from the sample tubes and carefully transfer each
adsorbent section to separate 2-mL vials. Discard the glass tube, urethane foam plug and glass wool plug.
3.4.2 Add
1.0 mL of extraction solvent to each vial using the same dispenser as used for preparation
of standards.
3.4.3 Immediately seal the vials with poly(tetrafluoroethylene)-lined caps.
3.4.4 Agitate the vials on a shaker or rotator for
30 minutes.
3.5 Analysis
3.5.1 Gas chromatographic conditions
GC conditions
|
| zone temperatures: |
initial 50°C,
hold 1 min, ramp at 10°C/min to 170°C, hold 17 min |
| injector: |
250 °C |
| detector: |
250 °C |
| run time: |
30 min |
| column gas flow: |
3.2 mL/min (hydrogen) |
| injection size: |
1.0 µL (10:1 split) |
| column: |
60-m
× 0.32-mm i.d. capillary DB-1 (df = 1 µm) |
| retention times: |
4.0 min (CS2); 7.0 min (DMF); 11.8 min (p-cymene);
26.5
min (1,6-hexanediol diacrylate
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FID conditions
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| hydrogen flow: |
30 mL/min |
| air flow: |
400 mL/min |
| nitrogen makeup flow: |
25 mL/min |
Figure 3.5.1
A chromatogram of 48.4 µg/mL 1,6-hexanediol
diacrylate in 99:1 CS2:DMF with 0.25 µl/mL p-cymene internal standard. (Key: (1) CS2; (2) DMF; (3) p-cymene; (4) 1,6-hexanediol diacrylate) |
3.5.2 Peak areas are measured by an
integrator or other suitable means.
Figure 3.5.2
Calibration curve
of 1,6-hexanediol diacrylate. (y = 779x - 1057) |
3.5.3 An internal standard (ISTD) calibration method
is used. A calibration curve can be constructed
by plotting ISTD-corrected response of standard injections versus micrograms of
analyte per sample. Bracket the samples
with freshly prepared analytical standards over the range of concentrations.
3.6 Interferences (analytical)
3.6.1 Any
compound that produces a GC response and has a similar retention time as the analyte
is a potential interference. If any
potential interferences were reported, they should be considered before samples
are extracted. Generally, chromatographic
conditions can be altered to separate interference from the analyte.
3.6.2 When
necessary, the identity or purity of an analyte peak may be confirmed by GC-mass
spectrometry or by another analytical procedure. The mass spectrum in Figure 3.6.2 was from the
NIST spectral library.
Figure 3.6.2
Mass spectrum of 1,6-hexanediol diacrylate. |
3.7 Calculations
The
amount of analyte per sampler is obtained from the appropriate calibration
curve in terms of micrograms per sample, uncorrected for extraction
efficiency. This total amount is then
corrected by subtracting the total amount (if any) found on the blank. The air concentration is calculated using the
following formula.
| where: |
CM is concentration by weight (mg/m3) |
| M is micrograms per sample |
| V is liters of air sampled |
| EE
is extraction efficiency, in decimal form |
4.
Recommendations for further study
Collection,
reproducibility, and other detection limit studies need to be performed to make
this a fully validated method.
References
1. Lewis,
R., Sax's Dangerous Properties of Industrial Materials, Tenth ed., Vol.
3, John Wiley & Sons Inc., New York,
2000, p 1951.
2. Material
Safety Data Sheet: Hexanediol Diacrylate, Chemwatch, Victoria, Australia, (accessed 12/17/03).
3. Lewis,
R., Sax's Dangerous Properties of Industrial Materials, Tenth ed., Vol.
3, John Wiley & Sons Inc., New York,
2000, p 1951.
4. Lewis,
R., Sax's Dangerous Properties of Industrial Materials, Tenth ed., Vol.
3, John Wiley & Sons Inc., New York,
2000, p 1951.
5. Material
Safety Data Sheet: 1,6-Hexanediol Diacrylate, Aldrich Chemical Co., Milwaukee, WI, (accessed 10/3/03).
6. OSHA
Chemical sampling Information,
http://www.osha.gov (accessed 12/17/03).
7. Burright,
D.; Chan, Y.; Eide, M.; Elskamp, C.; Hendricks, W.; Rose, M. C. Evaluation
Guidelines for Air Sampling Methods Utilizing Chromatographic Analysis; OSHA Salt Lake Technical Center,
U.S. Department of Labor: Salt Lake City, UT, 1999.
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