Clinical evaluation of Toxi.Prep: a semiautomated solid-phase extraction system for screening of drugs in urine.


Journal Article

A prototype Toxi.Prep (TP) system that utilizes solid-phase extraction (SPE) has been developed as a method for broad-spectrum drug screening and identification of tetrahydrocannabinol (THC) metabolites in urine. TP can simultaneously extract up to seven specimens while automating the process of sample extraction, washing, and elution onto a chromatogram. TP was compared with the Toxi. Lab A (TL-A) system for extraction of basic drugs only. In a blind study, 33 distinct drugs and metabolites were detected in 55 urines over 13 runs. Of the drug occurrences, 68.8% (141 of 205) were detected on both TP and TL-A. Of the 13 runs, quinidine and quinine, nortriptyline metabolites, and diphenhydramine were noted more frequently on TP than TL-A, whereas nicotine and metabolites, morphine, and methadone metabolites were more frequently noted on TL-A. Twenty specimens were analyzed for THC metabolites. Of the cases positive for THC metabolites, 100% (16 of 16) were positive by both methods. Time and motion studies for all runs proved an overall labor reduction for extraction and spotting by approximately 40%.

Full Text

Duke Authors

Cited Authors

  • Steinberg, DM; Sokoll, LJ; Bowles, KC; Nichols, JH; Roberts, R; Schultheis, SK; O'Donnell, CM

Published Date

  • November 1997

Published In

Volume / Issue

  • 43 / 11

Start / End Page

  • 2099 - 2105

PubMed ID

  • 9365394

Pubmed Central ID

  • 9365394

International Standard Serial Number (ISSN)

  • 0009-9147


  • eng

Conference Location

  • England