Standardization of a Method for Analysis of Cocaine in Urine Samples using Solid-Phase Extraction (SPE) and High Performance Liquid Chromatography (HPLC)

Abstract

The high costs of the consumption of pure cocaine, led to the production of cocaine base or bazuco (crack), a product of lower economic value, high demand and generally more used by consumers of low socioeconomic level. Bazuco is a white or brownish, semisolid or solid substance, whose active principle ingredient is cocaine. Cocaine is an alkaloid with a long history of use and abuse. Determination of both, in non-biological samples as well as in biological fluids remains a top priority task. In this work, the validation of the extraction method of cocaine in urine samples is reported, using the technique of solid phase extraction (SPE). Recovery rates between 99.4 and 99.8% were obtained using SPE to cocaine. The technique was standardized using chromatographic column C18, an ultraviolet detector (254 nm), a mobile phase of acetonitrile-acetic acid-water (58-40-2) at a flow of 0.4 mL/min. The linearity range was between 0.01 ug/mL and 1.0 ug/mL. Three quantification curves were created: 10 – 20 ppb, 20-100 ppb and 100-1000 ppb with determination coefficients r 2  of 0.9965, 0.9947 and 0.9973 respectively. The method was applied to urine samples from a group of volunteers who consumed crack in the city of Popayán, Cauca, Colombia.