A simple and sensitive method for the determination of propofol in human solid tissues by gas chromatography-mass spectrometry

Abstract

Propofol is a widely used intravenous agent for induction and maintenance of anesthesia and for sedation in intensive care patients, but it is also associated with abuse and dependency. A simple and sensitive method for the determination of propofol in human whole blood, brain, liver, and adipose tissue by gas chromatography-mass spectrometry using selected-ion monitoring mode is described. Propofol was extracted from 0.2-mL or 0.2-g sample size by a single-step basic extraction procedure using 100 μL heptane with thymol (50 ng) as an internal standard. The calibration curves of the specimens were linear in the concentration range of 10-5000 ng/mL or ng/g, and the limit of detection was 2.5 ng/mL in blood, 5.0 ng/g in brain and liver, and 10 ng/g in adipose tissue. Absolute recovery of propofol was determined in three samples and averaged over 95% for blood and brain, 66% for liver, and 51% for adipose tissue.Within-day and between-day precision was measured in five samples each at 50 and 500 ng/mL or ng/g in all specimens and was determined to be less than 10%. The developed propofol method was applied to a forensic autopsy case where a suspected propofol misinjection occurred eight days prior to death, and the tissue analysis was vital to the case.