New techniques of ambient mass spectrometry and their applications

Ambient mass spectrometry(AMS) is a kind of newly emerged technology performed under ambient conditions that allows the direct analysis of sample or sample surfaces with little or no sample pretreatment.Based on direct analysis in real time mass spectrometry(DART-MS),our laboratory investigated some new techniques for ionization of ambient mass spectrometry and explored their applications.First,rapid targeted screening methods were developed through combination of easy sample pre-treatment with DART-MS.Second,online coupling of normal phase liquid chromatography(NPLC) and MS was realized for chiral separation,greatly improving the ionization efficiency of the analytes in the normal phase mobile phase.For new ambient ionization source research,our laboratory fabricated plasma assisted multiwavelength laser desorption ionization mass spectrometry(PAMLDI-MS) system,which combined laser desorption and plasma-assisted ionization together.This system has been applied in the analysis of low molecular weight compounds separated on thin layer chromatography(TLC).In addition,a piece of graphite-coated paper was utilized for the sample introduction,which greatly improved the detection sensitivity of analytes in the above system.