Emit ETS plus ethyl alcohol assay for the determination of ethanol in human serum and urine

We evaluated the enzymatic Emit ETS Plus Ethyl Alcohol Assay (Emit) intended for the quantitative analysis of ethanol in human urine, serum, and plasma. The assay had been designed for use with the new Syva ETS Plus analyzer. The assay had a linear range up to 6.5 g/L and a low detection limit of 0.1 g/L. Assay within-run precision in serum with ethanol added to 0.25, 0.40, 1.00, 3.00, and 5.00 g/L yielded CVs (n = 32) of 6.1, 5.8, 3.7, 3.5, and 4.5%, respectively. Within-run precision of the assay using with ethanol added to 0.25, 0.40, 1.00, 3.00, and 5.00 g/L yielded CVs (n = 32) of 4.9, 5.0, 4.3, 3.3, and 5.0%, respectively. Between-run precision of aqueous controls yielded 0.41 +/- 0.02 g/L ethanol (target value, 0.40 g/L), CV = 4.5% (n = 31) and 3.05 +/- 0.06 g/L ethanol (target value, 3.00 g/L) CV = 2.1% (n = 31). Absolute recovery of the assay with 0.40 to 6.00 g/L ethanol added to serum and urine yielded mean recovery values of 105.5 and 101.5%, respectively. Results of the analysis of patient serum and urine specimens for ethanol by the Emit assay correlated well with those obtained by other methods. The Emit assay was found to be rapid, precise, and accurate for the determination of ethanol in clinical specimens. It was also found to be free of interferences from small molecular weight alcohols, aldehydes, ketones, and glycols. The Emit assay's linear range of up to 6.50 g/L ethanol was a major advantage over the ADx and aca assays; these assays were only linear to 3.00 g/L.