@article{ref1,
title="A sensitive assay for urinary cocaine metabolite benzoylecgonine shows more positive results and longer half-lives than those using traditional cutoffs",
journal="Drug testing and analysis",
year="2016",
author="Nickley, Joyce and Pesce, Amadeo J. and Krock, Kevin",
volume="9",
number="8",
pages="1214-1216",
abstract="Cocaine is a common drug of abuse. To detect its use, a screening detection concentration for the cocaine metabolite benzoylecgonine is commonly set at 150 ng/mL and its confirmatory cutoff is set at 100 ng/mL [1]. Studies have suggested that these cutoffs may be set too high, allowing some patients with this substance abuse problem to be missed [2,3] or improperly monitored. With the advent of LC-MS/MS technology it is possible to reliably detect and quantify lower concentrations of its metabolite benzoylecgonine [4] as part of a larger drug panel. One purpose of the study was to establish if there was a significant increase in detection of cocaine use with a tenfold more sensitive cutoff. A very sensitive dilute and shoot assay for benzoylecgonine was developed with a lower limit of quantitation of 5 ng/mL. Validation of the 5 ng/mL cutoff was achieved by plotting all the positive cocaine observations as a frequency distribution on a logarithmic scale. The number of positive results with measurable concentrations below the typical industry 100 ng/mL cutoff level but above the high sensitivity 5 ng/mL cutoff level was observed to be 51.9% of the observed positives. The lower cutoff also allowed a re-evaluation of the window of detection after cessation of use. It was observed to be between 17 to 22 days.<br><br>This article is protected by copyright. All rights reserved.<p /> <p>Language: en</p>",
language="en",
issn="1942-7603",
doi="10.1002/dta.2153",
url="http://dx.doi.org/10.1002/dta.2153"
}