Development of a Liquid Chromatography-Tandem Mass Spectrometry Method for the Simultaneous Determination of 40 Drugs of Abuse in Human Urine: Application to Real Cases.

Drugs of abuse are constantly evolving, while new synthetized substances are constantly emerging to avoid regulations. However, traditional drugs such as cocaine and amphetamine are still two of the most consumed drugs in the world. It is important, therefore, to provide suitable multiresidue methods for determining a wide range of drugs for use in toxicological and forensic analyses. The aim of this study is to develop a method for determining several families of drugs of abuse, including classic drugs, new psychoactive substances and some of their metabolites, in urine by liquid chromatography-tandem mass spectrometry. Urine is one of the most common biological matrices used in drug analysis because of its easy collection and a wide window of detection. In this study, we used solid-phase extraction to remove interferences and extract analytes from urine. Four different mixed-mode cation-exchange commercial sorbents were evaluated. The best results, in terms of apparent recoveries, were achieved with one of the strong cationic sorbents, ExtraBond SCX. The method achieved detection limits from 0.003 to 0.500 ng/mL and quantification limits from 0.050 to 1.500 ng/mL, which are suitable for determining these compounds at the usual levels found in the urine of drug users. The applicability of this method was demonstrated by analyzing real urine specimens from women following a detoxification program. Our results showed that the drug most consumed was cocaine, since it was detected in most urine specimens together with its main metabolite, benzoylecgonine. The polyconsumption of drugs from different families was also observed in some urine samples analyzed.