Microwave-assisted acid hydrolysis of toluene diamine conjugates in urine samples for biomarkers in toluene diisocyanate analysis.
Toluene diamines (TDAs) in urine have been used widely to determine the amount of toluene diisocyanate (TDI) absorbed by humans. Conventional hydrolysis to prepare a sample of urine takes approximately 16h. An attempt is made to apply microwave-assisted heating (MAH) to reduce the duration of analysis. Urine collected from rats exposed to a mixture of 2,4- and 2,6-TDI was diluted with non-exposed human urine 1/1250-, 1/500- and 1/250-fold. The urine samples were hydrolyzed by both conventional heating and MAH. The hydrolysis efficiency obtained using MAH significantly exceeded that obtained using conventional heating. Hydrolysis by MAH required only 20min, 48 times faster than with conventional heating. The use of the MAH method in hydrolysis was demonstrated to be reproducible, timesaving and efficient technique in measuring the concentration of urinary TDAs.
Yeh
Hui-Jung
HJ
Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC; Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC; Department of Childhood Education and Nursery, Chia Nan University of Pharmacy and Science, Tainan, Taiwan, ROC.
Lin
Wei-Chao
WC
Sheu
Shiann-Cherng
SC
Shih
Tung-Sheng
TS
Chen
Lien-Huei
LH
Chang
Ho-Yuan
HY