Development of a method for monitoring personal exposure to benzyl violet 4B and direct blue 15 in workplace air.

OBJECTIVES: The purpose of this research was to develop a method for monitoring personal exposure to benzyl violet 4B (BV) and direct blue 15 (DB) in workplace air for risk assessment. METHODS: We evaluated the utility of the proposed method by examining the following: recovery; method limit of quantification; reproducibility; and storage stability of the samples. RESULTS: An air sampling cassette containing a glass fiber filter was chosen as the sampler. BV and DB were extracted from the sampler filters with a solution of water and methanol (7:3, v/v) and then analyzed by a high-performance liquid chromatograph equipped with a photo-diode array detector. The overall recoveries from spiked samplers were 94-102% and 94-99% for BV and DB, respectively. The recovery after seven days of storage at 4°C exceeded 95%. The method limits of quantification were 0.250 and 1.25 µg/sample for BV and DB, respectively. The relative standard deviations, which represent the overall reproducibility defined as precision, were 0.6-4.1% and 0.8-2.9% for BV and DB, respectively. CONCLUSIONS: The proposed method enables 4 h personal exposure monitoring of BV and DB at concentrations of 1-2,000 µg/m3 for BV and 5-2,000 µg/m3 for DB, with a 240 l sampling. Thus, the proposed method is useful for estimating worker exposure to BV and DB.

Determination method for p-Phenylazoaniline and 2-methyl-4-(2-tolylazo)aniline in workplace air by high-performance liquid chromatography.

OBJECTIVES: The purpose of this research was to develop a method for the simultaneous determination of p-Phenylazoaniline (also called 4-aminoazobenzene, AAB) and 2-methyl-4-(2-tolylazo)aniline (also called o-aminoazotoluene, AAT) in workplace air for risk assessment. METHODS: The characteristics of the proposed method, such as recovery, limit of quantitation, reproducibility and storage stability of the samples were examined. RESULTS: An air sampling cassette containing two sulfuric acid-treated glass fiber filters was chosen as the sampler. The AAB and AAT were extracted from the sampler filters by methanol and then analyzed by a high-performance liquid chromatograph equipped with a photo-diode array detector. The overall recoveries from spiked samplers were 77-98 and 85-98% for AAB and AAT, respectively. The recovery after 5 days of storage in a refrigerator exceeded 96%. The overall limits of quantitation were 5.00 and 2.50 µg/sample for AAB and AAT, respectively. The relative standard deviations, which represent the overall reproducibility defined as precision, were 0.6-1.8 and 0.5-2.2% for AAB and AAT, respectively. CONCLUSIONS: The proposed method enables 4-h personal exposure monitoring of AAB and AAT at concentrations of 21 to 2,000 µg/m3 for AAB and 10 to 2,000 µg/m3 for AAT, respectively. The proposed method is useful for estimating worker exposure to AAB and AAT.

Determination method for mono- and diethanolamine in workplace air by high-performance liquid chromatography.

OBJECTIVES: The purpose of this research was to develop a simultaneous determination method for monoethanol-amine (MEA) and diethanolamine (DEA) in workplace air for risk assessment. METHODS: The characteristics of the proposed method, such as recovery, quantitation limit, reproducibility and storage stability of the samples, were examined. RESULTS: An air sampling cassette containing two sulfuric acid-treated glass fiber filters was chosen as the sampler. The MEA and DEA were extracted from the sampler filters, derivatized with 9-fluorenylmethyloxycarbonyl chloride and then analyzed by a high-performance liquid Chromatograph equipped with a fluorescence detector or photo-diode array detector. The overall recoveries from spiked samplers were 86-99 and 88-99% for MEA and DEA, respectively. The recovery after 5 days of storage in a refrigerator exceeded 95%. The overall limits of quantitation were 0.750 and 0.100 jug/sample for MEA and DEA, respectively. The relative standard deviations, which represent the overall reproducibility defined as precision, were 0.3-1.6 and 0.4-5.7% for MEA and DEA, respectively. CONCLUSIONS: The proposed method enables 4-h personal exposure monitoring of MEA and DEA at concentrations equaling 1/3,000-2 times the threshold limit value-time-weighted average (TLV-TWA: 3 ppmfor MEA, 1 mg/m(3) for DEA) adopted by the American Conference of Governmental Industrial Hygienists and also by the Japan Society for Occupational Health. The method is useful for estimating worker exposure to MEA and DEA.

Determination method for xylidines in workplace air.

OBJECTIVES: The purpose of this research was to develop a determination method for xylidines (XLDs) in workplace air for risk assessment. METHODS: The characteristics of the proposed method, such as recovery, detection limit, reproducibility, and storage stability of the samples were examined. RESULTS: An air sampler cassette containing two sulfuric acid-treated glass fiber filters was chosen as the sampler. The XLDs were extracted from the sampler filters, derivatized with heptafluorobutyric anhydride, and then analyzed by a gas chromatograph equipped with a mass spectrometer. The average recoveries of XLDs from the spiked sampler were 83-101% for personal exposure monitoring. The recovery after 5 days of storage in a refrigerator exceeded 90%. The overall limit of quantitation (LOQ) was 0.600 g/sample. The relative standard deviation, which represents the overall reproducibility defined as precision, was 0.8-10.3%. CONCLUSIONS: The proposed method enables 4-hour personal exposure monitoring of XLDs at concentrations equaling 0.001-2 times the threshold limit value-time-weighted average (TLV-TWA: 0.5 ppm) adopted by the American Conference of Governmental Industrial Hygienists, and is useful for estimating worker exposure to XLDs.

Determination method for nitromethane in workplace air.

OBJECTIVES: The purpose of this research was to develop a determination method for nitromethane (NM) in workplace air for risk assessment. METHODS: A suitable sampler and appropriate desorption condition were selected by a recovery test in which a spiked sampler was used. The characteristics of the proposed method, such as recovery, detection limit, and reproducibility, and the storage stability of the sample were examined. RESULTS: A sampling tube containing bead-shaped activated carbon was chosen as the sampler. NM in the sampler was desorbed with acetone and analyzed by a gas chromatograph equipped with a flame ionization detector. The recoveries of NM from the spiked sampler were 81-97% and 80-98% for personal exposure monitoring and working environment measurement, respectively. On the first day of storage in a refrigerator, the recovery from the spiked samplers exceeded 90%; however, it decreased dramatically with increasing storage time. In particular, the decrease was more remarkable for the smaller spiked amounts. The overall LOQ was 2 microg/sample. The relative standard deviation, which represents the overall reproducibility, was 1.1-4.0%. CONCLUSIONS: The proposed method enables 4-hour personal exposure monitoring of NM at concentrations equaling 0.001-2 times the threshold limit value-time-weighted average (TLV-TWA: 20 ppm) proposed by the American Conference of Governmental Industrial Hygienists, as well as 10-minute working environment measurement at concentrations equaling 0.02-2 times TLV-TWA. Thus, the proposed method will be useful for estimating worker exposure to NM.

A survey on exposure level, health status, and biomarkers in workers exposed to 1-bromopropane.

BACKGROUND: The aim of this study was to evaluate the health effects of exposure mainly to 1-bromopropane, which is an alternative to ozone-depleting solvents, and to establish biomarkers for assessing 1-bromopropane exposure. METHODS: Twenty-four female and 13 male workers of a 1-bromopropane-factory were interviewed, and their urine and blood samples were collected. Measured parameters included 1-bromopropane levels in the factory, as well as individual exposure levels, urinary 1-bromopropane levels, enzymatic activity and M subunit's concentration of serum creatine kinase (CK). RESULTS: Frequent symptoms reported by workers exposed to 1-bromopropane were nose, throat, and eyes irritation or malaise and/or headache. Urinary 1-bromopropane levels correlated significantly with individual exposure levels, but enzymatic activity or CK-M subunit did not. CONCLUSIONS: The symptoms suggested irritation of the mucous membrane and possible adverse effects on the central nervous system. There were no severe chronic symptoms suggestive of neurological damage in workers exposed to less than 170 ppm. Urinary 1-bromopropane level may be a good indicator of exposure. Am. J. Ind. Med. 45:63-75, 2004.