Comparison of High-Resolution Mass Spectrometry with Immunoassay in Qualitative Urine Drug Screening

Abstract

Liquid Chromatography Time-of-Flight Mass Spectrometry (LC-TOF) utilizes a high-resolution mass spectrometer and chromatography to identify drugs in urine, based on their exact masses and retention times. The current "gold standard" method of qualitative urine drug screening is the immunoassay, which uses antibodies developed against drugs or their metabolites to identify them. Since this antibody-based methodology may have significant cross-reactivities and loss of specificity associated with it, it has been proposed to replace it with LC-TOF. This research compares the detection of drugs in urine with immunoassay and LC-TOF, following the development and validation of a qualitative LC-TOF assay.