Determination of chloral hydrate and its metabolites (trichloroethanol and trichloracetic acid) in human plasma and urine using electron capture gas chromatography.

Capillary gas chromatography with electron capture detection is described for the quantification of chloral hydrate (CH) and is metabolites trichloroethanol (TCE) and trichloroacetic acid (TCA) in 0.1-1 mL of plasma samples. The method, with 2,2'-dichloroethanol (DCE) as internal standard, involved extraction of chloral hydrate and trichloroethanol with diethyl ether and methylation of trichloroacetic acid with 3-methyl-1-tolyltriazene (MTT), followed by diethyl ether extraction. The method has a detection limit of 5 ng/mL for CH and TCE and 10 ng/mL for TCA and also allows the determination of TCE-glucuronide in 0.1-1 mL of plasma samples. It exhibits good linearity and precision. The method was applied to samples of plasma from a neonate after a single dose of 40 mg/kg of chloral hydrate and from an adult after a single dose of 6.25 mg/kg.