title: Drug of abuse confirmation in human urine using stepwise solid-phase extraction and micellar electrokinetic capillary chromatography.
abstract: This paper demonstrates that most common drugs of abuse can be absorbed simultaneously onto a mixed-mode bonded-phase matrix and eluted sequentially in two to three steps for subsequent analysis by micellar electrokinetic capillary chromatography (MECC). Having on-column multiwavelength UV absorption detection, this is shown to be an attractive approach for confirmation testing of barbiturates, hypnotics, amphetamines, opioids, benzodiazepines, and metabolites of cocaine in a single aliquot of human urine. For these compounds, no hydroysis of the urine specimen or sample derivatization is required. Under the examined conditions using 5 mL of urine, excellent recoveries (80-90% level) and detection limits (about 100 ng/mL) are obtained. For patient urines which tested positively for different classes of drugs using immunological screening methods, a two-step extraction scheme is shown to provide extracts suitable for rapid MECC confirmation of the drugs of abuse.
authors.affiliation: Department of Clinical Pharmacology, University of Bern, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Wernly
authors.forename: W
authors.initials: W
authors.lastname: Thormann
mesh_terms: D002845:Chromatography / Q000379:methods; D004586:Electrophoresis; D006801:Humans; D013287:Illicit Drugs / Q000652:urine*; D015813:Substance Abuse Detection / Q000379:methods*
chemical_list: D013287:Illicit Drugs