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

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.

The characteristics of the proposed method, such as recovery, quantitation limit, reproducibility and storage stability of the samples, were examined.

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.

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.