Authors: Rosario Brunetto Lubin Gutiérrez Yelitza Delgado Máximo Gallignani José Luis Burguera Marcela Burguera
Publish Date: 2003/01/29
Volume: 375, Issue: 4, Pages: 534-538
Abstract
A columnswitching highperformance liquid chromatographic method with UV detection for the determination of cocaine COC and benzoylecgonine BZE in human blood plasma samples is described The method uses an alkyldiolsilica ADSC18 extraction precolumn A 50µL plasma sample was introduced to the ADS precolumn in order to separate the analytes from proteins and endogenous compounds The fraction containing COC and BZE was backflushed and transferred to an Alltech mixedmode C18/cationexchange analytical column for final separation The validation of the method revealed quantitative recoveries from 950 to 990 for COC at three different concentrations 05 10 and 20 µg mL–1 and from 960 to 990 for BZE at the same concentration levels with coefficients of variation 400 n=5 The detection limit signal to noise ratio S/N3 was 003 µg mL–1 for all the compounds with an injection volume of 50 µL However it was possible to enhance the sensitivity further by injecting larger plasma volumes up to 200 µL at the same optimal conditions The overlap of sample preparation analysis and reconditioning of the extraction column increase the overall sample throughput to 5 samples h–1 The developed method has been applied to human blood plasma samples from subjects suspected of cocaine abuse
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