Rapid Confirmation/Quantitation of Ecgonine Methyl Ester, Benzoylecgonine, and Cocaine in Urine Using On-Line Extraction Coupled with Fast HPLC and Tandem Mass Spectrometry

Abstract

A rapid, rugged, and highly specific assay for the quantitation of cocaine (COC) and especially its primary metabolites benzoylecgonine (BZE) and ecgonine methyl ester (EME) in human urine has been established. Here, we investigated the use of on-line sample extraction coupled to rapid chromatography systems for tandem mass analysis of COC, EME, and BZE in human urine. Using this method, sample preparation consisted of a sole centrifugation step. Combined extraction and chromatographic run times were < 3.5 min. The lower limits of detection were 0.5 ng/mL, 2.0 ng/mL, and 0.5 ng/mL for EME, BZE, and COC, respectively. Linear calibration curves ranging from 7.5 ng/mL to 1000 ng/mL were produced for the test analytes. Within-day and between-day precision and accuracy of the assay were determined using human urine quality-control specimens at 5, 10, or 15; 150; and 1000 ng/mL. The analyses were performed over the course of five days, rendering %CVs < 10% for EME, BZE, and COC. Percent mean accuracy for the three analytes of 97 to 113% were obtained. Our data suggest that on-line sample extraction coupled with rapid high-performance liquid chromatography-tandem mass spectrometry may be a viable alternative for EME, BZE, and COC analyses in human urine.

Determination of cocaine and its metabolites using cation‐selective exhaustive injection and sweeping‐MEKC

“…Although HPLC with UV detection has been employed to determine cocaine and its metabolites with satisfactory resolution [11,12], the LODs have been too high. Cocaine and its metabolites have also been determined successfully using LC/MS coupled with ESI or atmospheric pressure chemical ionization tandem mass spectrometry (LC/MS/MS) to increase the accuracy of their quantitative analyses and to raise the sensitivity of analyses of biological fluids [13][14][15][16][17][18][19]. As an analytical tool, CE has several advantageous features, including rapid analyses, good separation efficiencies, and minimal sample requirements.…”

Quantitative analysis of cocaine and its metabolites in whole blood and urine by high-performance liquid chromatography coupled with tandem mass spectrometry

“…The use of tandem MS detection results in an excellent sensitivity and specificity. Several LC/MS/MS applications for cocaine have been published, but they have either been qualitative analysis of only COC and BZE in plasma [9,10] or quantitative analysis of the cocaine and metabolites in other matrices such as urine, oral fluid, hair and meconium [11][12][13][14][15]. Published methods in blood are mainly performed in plasma and typically limited to cocaine and one or two metabolites [3,8,[16][17][18].…”

Fast LC/MS in the analysis of small molecules

“…Souverain et al analyze human plasma for methadone and its primary metabolite by the direct injection of plasma onto a sample extraction column followed by back-flushing at 1.5 min onto the analytical column for a total run time of 6.0 min [151]. Jeanville et al [152] perform an on-line extraction with the direct injection of urine for confirmation and quantitation of ecgonine methyl ester, benzoylecgonine, and cocaine with a total run time of 3.2 min.…”