Trace Detection of Organophosphorus Pesticides in Vegetables via Enrichment by Magnetic Zirconia and Temperature-Assisted Ambient Micro-Fabricated Glow Discharge Plasma Desorption Ionization Mass Spectrometry

In this study, an innovative rapid detection technology for quickly screening and quantifying organophosphorus pesticides (OPPs) in vegetables was developed based on ambient micro-fabricated glow discharge plasma desorption / ionization mass spectrometry (MFGDP-MS), where Fe3O4 / ZrO2 synthesized by a one-step coprecipitation was used for enrichment. It can not only effectively enrich OPPs, but can be separated by an external magnetic field, thereby simplifying the traditional steps of centrifugation and cleanup in sample preparations. The introduction of temperature control system (TCS) can tackle the problem of low ionization efficiency in MFGDP and expand its the application range. Under optimized experimental conditions, the limits of detection (LODs) of standard solution as low as of 0.0068-0.7500 μg L -1 mm -2 were achieved, with relative standard deviations (RSDs) less than 17.8 %. Moreover, vegetable extracts were spiked to evaluate the accuracy of the method, and good recoveries (76.9-123.5 %) were obtained. Remarkably, it took no more than 7 minutes from sample preparation to testing, resulting in significantly improved ability of quantitative detection of plentiful samples.