Determination of the halothane metabolites trifluoroacetic acid and bromide in plasma and urine by ion chromatography

Abstract Halothane (CF 3 CHClBr), a widely used volatile anesthetic, undergoes extensive biotransformation in humans. Oxidative halothane metabolism yields the stable metabolites trifluoroacetic acid and bromide which can be detected in plasma and urine. To date, analytical methodologies have either required extensive sample preparation, or two separate analytical procedures to determine plasma and urine concentrations of these analytes. A rapid and sensitive method utilizing high-performance liquid chromatography-ion chromatography (HPLC-IC) with suppressed conductivity detection was developed for the simultaneous detection of both trifluoroacetic acid and bromide in plasma and urine. Sample preparation required only ultrafiltration. Standard curves were linear ( r 2 ≥0.99) from 10 to 250 μ M trifluoroacetic acid and 2 to 5000 μ M bromide in plasma and 10 to 250 μ M trifluoroacetic acid and 2 to 50 μ M bromide in urine. The assay was applied to quantification of trifluoroacetic acid and bromide in plasma and urine of a patient undergoing halothane anesthesia.