A simple method for the determination of ethylene-thiourea (ETU) in biological samples

A direct, simple, and rapid high-performance liquid chromatographic method has been developed for the determination of ethylene-thiourea (ETU) in biological fluids. Samples were chromatographed on a Lichrosorb RP8 (5 μm) column after extraction with dichloromethane. The mobile phase was a mixture of hexane/isopropyl alcohol/ethyl alcohol (93:6:1 v/v) added with 0.6 mL/L butylamine. Detection was done with a UV detector set at 243 nm. This method was validated to standard criteria. Calibration curves for ETU in 100 μL of 0.9% saline, 500 μL plasma, and 10 mL urine were linear (r2 > 0.99) from 0.05 to 30 μg/mL, 0.025 to 30 μg/mL, and 1 to 100 ng/mL, respectively. The lower limit of detection was 20 ng/mL in plasma, 25 ng/mL in 0.9% saline, and 0.5 ng/mL in urine.