METHODS FOR THE DETERMINATION OF DIMETHYLETHYLAMINE AND DIMETHYLETHYLAMINE-N-OXIDE IN AIR, PLASMA AND URINE SAMPLES

Sensitive routine gas-liquid chromatographic methods for the determination of dimethyiethylamine (DMEA) in air and of DMEA and dimethylethylamine-N-oxide (DMEAO) in plasma and urine, have been developed. DMEA was extracted in di-n-butyl ether and analysis was performed on an alkali-treated packing material (Carbowax 20M/0.8% K.OH) with a nitrogen-sensitive detector. The detection limit for DMEA in air was 0.01 mg/m3 (151 sample). DMEAO in blood and urine was determined as difference of DMEA after and before reduction of the sample. The standard curves were linear for DMEA levels up to 400mg/l (5.5mmol/1) and the detection limit was 0.01 mg/1 (0.1μmol/l). Urinary DMEA and DMEAO concentrations could be determined with a precision of 1–3 and 2-4%, respectively. The precisions for DMEA and DMEAO in plasma were 6 and 4-6%, respectively. The methods were validated to exposure levels of DMEA of up to 100 mg/m3 and corresponding plasma levels and urinary excretion of DMEA and DMEAO. © 1991, Taylor & Francis Group, LLC. All rights reserved.