Routine Detection of Benzolyecgonine in Urine at a Sensitivity of 35 ng/mL by a Combination of EMIT and Gas Chromatography/Mass Spectrometry

Abstract

The limit of detection of a published gas chromatographic/mass spectrometric (GC/MS) procedure for the detection of benzoylecgonine in urine was extended to 35 ng/mL. The GC/MS procedure then was used not only to confirm EMIT positives, but also to detect the presence of benzoylecgonine in urines that gave EMIT readouts below the low calibrator value, but higher than halfway between the negative and low calibrator values. Of 16 such patient urines, 12 were positive by the GC/MS procedure.