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100 ppm (491 mg/m
Samples are collected by drawing a known volume of air through a
Tenax GC tube. Samples are desorbed with a solvent mixture of
(5:95) Isopropanol:Carbon Disulfide (IPA):(CS
) and analyzed by gas
Recommended air volume
and sampling rate:
120 minutes at 0.1 L/min (12 L)
Partially Validated. This method has been only partially evaluated and
OSHA Salt Lake Technical Center
Salt Lake City UT-84115
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1 General Discussion
Recently, the OSHA Analytical Laboratory received a set of field samples that required
analysis for acetophenone. The air samples had been collected on charcoal tubes and
isopropanol impingers. Desorption studies were done on charcoal tubes using acetone,
carbon disulfide, 5:95 isopropanol:carbon disulfide, and methylene chloride as desorbing
solvents. The best results were obtained with 5:95 isopropanol:carbon disulfide, but the
recovery was only 68%, which indicated that charcoal tubes should not be recommended
for the collection of acetophenone air samples. An evaluation of isopropanol impingers
was not performed because it was preferable to find an adsorbent procedure for sample
collection. NIOSH method 291 for α -chloroacetophenone uses Tenax GC tubes. The
Tenax GC tubes were tried for acetophenone, and appeared to be a suitable method of
Acetophenone is a narcotic in high concentrations (Ref. 5.1). The oral LD
causing dermatitis to humans following skin contact (Ref. 5.3). Animal data indicates that
acetophenone may cause eye irritation and possibly transient corneal injury (Ref. 5.4).
No workplace exposure level could be found in the literature, but acetophenone is used in
the following processes: perfumery, solvent, intermediate for pharmaceuticals, resin,
polymerization catalyst, and flavoring (Ref. 5.1)
phenyl methyl ketone
82.2 °C (180 °F) (COC)
Slightly soluble in water, freely soluble in alcohol,
chloroform, ether, fatty oils, and glycerol.
Combustible, colorless liquid, with sweet, pungent
odor and taste
which will give a peak whose height is approximately five times the baseline noise.
g/mL is 407297 area units per Φg/mL of acetophenone. The sensitivity is determined by
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2 Sampling Procedure
a 4-mm i.d., containing 2 sections of Tenax GC separated by a 2-mm plug of urethane
foam. The absorbing section contains 30 mg of Tenax GC, the backup section 15 mg. A
3-mm plug of urethane foam is placed between the outlet end of the tube and the backup
section. A plug of silylated glass wool is placed in front of the absorbing section.
2.3 Sampling technique
be from the same lot.
the Tenax GC tubes should be positioned nearer the sampling pump.
lengthwise with an official Form OSHA 21 label.
samples. This tube should be subjected to exactly the same handling as the samples
(break, seal, and transport) except that no air is drawn through it.
with PTFE-lined caps. These samples must not be shipped in the same container used for
the Tenax GC tubes.
2.4 Desorption efficiency
Treatment Recovery Recovery
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2.5 Retention efficiency
drawn through four of the tubes at 0.1 L/min. Twelve liters of humid air (about 85% relative humidity)
were drawn through the other four tubes at 0.1 L/min.
12 L Humid Air
refrigerator for six days and two tubes were stored in a closed drawer at ambient temperature for six
Treatment % Recovery % Recovery
the collection of the analyte. Report possible interferences with submitted samples.
2.9 Safety precautions
cuts to the hands.
avoid injury to the eyes from glass splinters.
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the work performance of the employee.
3 Analytical procedure
hexylbenzene). The column used for validation studies was 1/8 inch x 10 ft stainless steel
containing 3% SP-2100 on 100/120 Supelcoport.
3.3 Standard preparation
volumetric flask of the desorbing reagent and making it to volume.
3.4 Sample preparation
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Column - 150
Injection size - 2.0 µl
Elution time - 1.4 minutes
an interference. Possible interferences should be listed on the sample data sheet. GC
parameters should be adjusted, if necessary, so these interferences will pose no problems.
Retention time data on a single column is not considered proof of chemical identity.
Samples results greater than 100 ppm should be confirmed by GC/Mass Spectrometry or
other suitable means.