This paper discusses the precision, accuracy and specificity of the Quantitative Enzyme Diagnostic (QED) test for measuring alcohol in saliva. This enzymatic method is very suitable for in-site workplace testing for alcohol use. The test's performance conditions were assessed in controlled experiments under in vitro and in vivo conditions. The in vitro experiments tested the response of QED with aqueous solutions of ethanol and other chemicals. Healthy male medical students participated in the in vivo experiments, and each drank 0.8g of ethanol per kg of body weight within 30min. Samples of blood were taken at frequent intervals between 10min and 420min after the start of drinking. The concentration of ethanol in breath was determined with an infrared analyser, the BAC Datamaster; this began 15min after the end of drinking, then was repeated whenever blood was drawn. The first samples of saliva were taken 15min after the end of drinking. The in vitro test confirmed the high precision and accuracy of the QED test for the ethanol concentration range 0 to 140mg/dl. However, the in vivo time profiles of ethanol concentration in saliva and blood were not identical. There was somewhat better agreement between saliva and breath profiles.
Samenvatting