Development of a Rapid MS-Based Screen of Tricyclic Antidepressants as an Alternative to Immunoassay Screening
Although enzyme immunoassay (EIA) is a prevalent screening technique, it is also prone to issues such as high false positive rates because of lack of analyte specificity. Mass spectrometry was therefore investigated as an alternative screening technique for the ability to improve analyte specificity on a comparable time scale. In this study, a rapid on-line sample preparation and injection (ROSPI) method was developed using a commercially available guard cartridge on a conventional liquid chromatography–tandem mass spectrometry (LC–MS/MS) system. Using a two-point calibration curve to provide semi-quantitation, a robust method was developed and validated that improved upon the high false positive rate observed in immunoassay screening.