title: Evaluation of selected-ion storage ion-trap mass spectrometry for detecting urinary anabolic agents.
abstract: Limits of detection are important issues for GC/MS screening for anabolic agents and for confirmation of various drugs of abuse. We compared a quadrupole ion trap (QIT) operated in two different selected-ion storage modes and a quadrupole mass filter (QMF) operated in the selected-ion monitoring mode. Results with the model compound tetrachlorobenzene indicate that, for simultaneous monitoring of more than four ions, the QIT operated in a frequency-modulated selected-ion storage mode has better limits of detection than the QMF. Use of a single-ion storage technique gave results similar to those of the QMF. We also evaluated both QIT selected-ion storage approaches for the limits of detection of the trimethylsilyl derivatives of four anabolic steroid metabolites and the beta-agonist clenbuterol. We found no improvement in detection limits over that of a similar method with selected-ion monitoring and a QMF when four anabolic steroid metabolites and clenbuterol were extracted from a urine matrix. The lack of improvement in the limit of detection resulted from matrix background signals at masses similar to those of the steroids.
authors.affiliation: Athletic Drug Testing and Toxicology Laboratory, Indiana University Medical Center, Indianapolis 46202-5120, USA. lbowers@iupui.edu
authors.forename: L D
authors.initials: LD
authors.lastname: Bowers
authors.forename: D J
authors.initials: DJ
authors.lastname: Borts
mesh_terms: D045930:Anabolic Agents / Q000652:urine*; D002722:Chlorobenzenes / Q000032:analysis; D005069:Evaluation Studies as Topic; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D018629:Spectrometry, Mass, Secondary Ion / Q000379:methods; D014297:Trimethylsilyl Compounds / Q000032:analysis
chemical_list: D045930:Anabolic Agents; D002722:Chlorobenzenes; D014297:Trimethylsilyl Compounds; C030386:1,2,3,4-tetrachlorobenzene