High-Throughput Screening of Illegal Drugs in Complex Matrix by Liquid Chromatography Tandem Quadrupole-Time of Flight Mass Spectrometry

Tandem quadrupole-time of flight(QTOF) mass spectrometry can provide the high accurate mass (＜2×10^－6) of parent and product ions for small and large molecules with excellent sensitivity and high mass resolution. Especially for the trace analysis in complex matrix(e.g. food, serum, fluid, environmental matrix), HPLC-QTOF plays an important role in identification and determination. In this study, a 250-illigal drug database based on accuracy mass was established, and a process for rapid screening and confirming of non-target illegal drugs was presented using urine and oral fluid preparation. The real samples were rapidly screened for illegal drugs using the molecular feature Extraction(MFE) algorithm of the Agilent Mass Hunter software, the established drug database, and accurate mass spectra using liquid-chromatography(LC), electrospray(ESI), quadrupole-time-of-flight mass spectrometry(Q-TOF LC/MS). The TOF data was processed by MFE, based on which the ions from noise and background were greatly removed. Using the MFE algorithm, a compound list containing interesting ions were contracted and the related chemical formula were calculated based on accuracy mass and isotope ratio calculation. Accurate masses of the ions detected and identified by MFE were compared to the exact masses of compounds in the database. Positive compounds were then further confirmed using the MS/MS(Q-TOF LC/MS) mode. Finally, the product ions from MS/MS mode are used for the determination of illegal drugs in the positive samples, and the methodology(linearity, repeatability and sensitivity) were investigated.