Determination of ethanol in human blood and urine by automated headspace solid-phase microextraction and capillary gas chromatography

In the present study we described the use of headspace solid-phase microextraction (HS-SPME) as an alternative to the conventional headspace for the analysis of ethanol in biological fluids. The methodology proposed was applied to determinate pharmacokinetics parameters in an experiment involving healthy subjects, which consumed large dose of ethanol in a short period of time. Blood and urine samples were collected and analyzed by HS-SPME and gas chromatography. It was found linearity over a concentration range of 0.5–800 mg/dL (r^2 = 0.9983) for HS-SPME and 1.0–500 mg/dL (r^2 = 0.9970) for HS. The detection limits of ethanol were 0.1 and 0.5 mg/dL (HS). Pharmacokinetics parameters demonstrated that, 62.5% of the subjects had BAC peak time of 60 min and 75% had urine ethanol peak time of 90 min, with the urine–blood alcohol ratios ranging from 0.16 to 2.79. HS-SPME demonstrated to be a suitable technique for determination of ethanol in biologic fluids. Comparative results obtained for HS-SPME and conventional headspace methodologies, presented good agreement (y = 0.9884x, r^2 = 0.9682) but HS-SPME demonstrated to be more sensitive than HS.