title: Experience with a sulfonamide diuretic in a large urine drug testing program.
abstract: Gas chromatography/mass spectrometry (GC/MS) with selected ion monitoring is a common confirmation method for tetrahydrocannabinol (THC) metabolites in urine. Department of Defense laboratories use this method for analysis of 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid (THCA) following ion exchange column purification and methylation. Furosemide, a common diuretic which is excreted into urine, will be isolated with THCA in the extraction procedure, will appear in the chromatographic window [retention time relative to 11-nor-delta-9-tetrahydrocannabinolmethyl ether-9-carboxylic acid methyl ester (THCA-Me) of 1.13], and will exhibit the six ions monitored for THCA-Me and its trideuterated analog. The results indicate that methylated furosemide and other common diuretics can easily be distinguished from THCA-Me. They also allow one to explain in court the extraneous peaks in a chromatogram and to correct for the overutilization of derivatizing reagent.
authors.affiliation: United States Army Forensic Toxicology Drug Testing Laboratory, Wiesbaden, Federal Republic of Germany, APO New York 09457.
authors.forename: B I
authors.initials: BI
authors.lastname: Podkowik
authors.forename: M L
authors.initials: ML
authors.lastname: Smith
authors.forename: R O
authors.initials: RO
authors.lastname: Pick
mesh_terms: D004232:Diuretics / Q000652:urine; D013759:Dronabinol / Q000031:analogs & derivatives* / Q000652:urine; D005665:Furosemide / Q000652:urine*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D011863:Radioimmunoassay; D013055:Spectrophotometry, Infrared; D019966:Substance-Related Disorders / Q000652:urine*; D014116:Toxicology
chemical_list: D004232:Diuretics; C016780:11-nor-delta(9)-tetrahydrocannabinol-9-carboxylic acid; D013759:Dronabinol; D005665:Furosemide