Screening for and confirmation of drugs of abuse in human urine is a timely topic in which capillary separation techniques play a key role. Capillary ลฝ . electrophoresis CE represents the newest technology employed in this field of analysis. Simple multianalyte electrokinetic capillary-based competitive immunoassays, assays based upon drug extraction and achiralแchiral CE with on-column multiwavelength detection, and a capillary electrophoresis-ion trap mass spectrometry assay were developed. These techniques are shown to comprise an analytical scheme beginning with presumptive immunological drug testing, followed by drug differentiation with spectral identification, and ending with complete confirmatory drug testing that is based upon tandem mass spectrometry. With data obtained from the urine of a polydrug abuser who was found to have ingested amphetamine, methadone, and other drugs, the suitability and limitations of the electrokinetic capillary methods for screening and confirmation of urinary methadone, its metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine and amphetamine are discussed. CE coupled to tandem mass spectrometry is further shown to represent a comprehensive approach for analysis of other drugs in the patient urine. แฎ 2000