MS/MS-libraries with triple quadrupole-tandem mass spectrometers for drug identification and drug screening

Abstract

Two MS/MS libraries of drugs created by electrospray ionisation (ESI) and collision-induced dissociation (CID) of the quasimolecular ions spectra of more than 400 drugs were acquired in positive or negative mode in two laboratories independently. Recently, one of these MS/MS libraries was applied successfully for the identification of drug metabolites and the other has been used for qualitative analysis of drugs in urine samples with data dependent experiments (DDE). In this work, the reproducibility of CID spectra has been tested with three instruments (including two different instruments) in three laboratories. For comparisons of CID-spectra, library searching with a combination of two libraries was performed and fit values were compared. With regard to library fit values CID-spectra were found to be highly reproducible between the instruments, when similar CID gas pressure and collision energy were applied. In addition, the long-time reproducibility of CID over 30 months with the API 365 was demonstrated. Furthermore, comparisons of in-source CID and CID by MS/MS was given. It can be concluded, that both MS/Ms libraries created with APIs 365 can be used with both types of triple-quadrupole instruments from Sciex (API 365 and 2000) for drug identification. Two applications of this MS/MS spectra libraries in combination with data dependent experiments are summarised.