Rapid screening method for cocaine and benzoylecgonine in saliva samples

We are presenting a new method for cocaine and benzoylecgonine analysis in saliva samples based on room temperature phosphorimetry. The determination of the drugs is performed on filter paper, which is a suitable substrate for most saliva collection procedures. Extraction from the solid substrate is not necessary, since both compounds are detected on the paper substrate. Complete analysis can be performed with only a few microliters of saliva, which is an attractive feature in cases of limited sample availability. The limits of detection are estimated at the sub-ng level, which shows the feasibility of detecting cocaine and benzoylecgonine at the cut-off levels stipulated by the National Institute on Drug Abuse (300 ng/ml), When compared to the existing methodology, the phosphonimetric method presents several advantages which include simplicity, short analysis time, low cost, and the viability of interfacing it with portable instrumentation for field screening applications. (C) 1998 Elsevier Science B.V. All rights reserved.