Method for Alcohol Determination in Biological Liquids by Sensing with a Solid-State Detector

I describe a new method for quantitative alcohol de-termination in equilibrated headspace gas of biological liquids by means of a solid-state metal-oxide semicon-ductor (MOS) detector. After equilibration of the NaCI-saturated specimen at 40 #{176}Cor other convenient tem-perature in a closed vessel, a Taguchi MOS sensor is momentarily exposed to the headspace vapor. The re-sulting dc voltage change from the baseline conditions accurately reflects the alcohol concenfration of the liquid specimen, and can be read in direct alcohol-concentration units. Calibration is linear to 3.00 g/liter (300 mg/dl). Values for analytical recovery ranged from 98 to 102%. Correlation of results for blood alcohol concentration by this method (ye) and an automated gas-chromatographic reference method (x,) was y, g/liter = 0.991x + 0.0 14, with r = 0.997 for 103 blood specimens having concen-trations ranging from 0 to 2.89 g/liter (0-289 mg/dl), with a mean difference (x1- y) =-6 mg/liter(0.6 mg/dl).The method is sensitive to 0.01 g/liter (1 mg/dl) and can be readily automated. An internal standard is not required. AdditIonal Keyphrasas: screening #{149}toxicology #{149}solid-state metal-oxide semiconductor detector #{149}vapor analysis #{149}gas-chromatography compared Ambient sensing of alcohol1 in breath by physical-chemical means with use of solid-state devices has been recently introduced for breath-alcohol screening tests (1, 2). Thus, the A.L.E.R.T.TM portable electronic breath-alcohol tester (3, 4) detects alcohol with an n