Ambient mass spectrometry is one of the mainstream techniques in modem mass spectrometry development. The developing purpose of ambient mass spectrometry is improving the analysis efficiency and simplifying operation process. So that, there are many techniques about ambient mass spectrometry had been published and commercialized. And direct electrospray probe mass spectrometry (DEP/MS) is one of ambient mass spectrometry techniques which is emphasized its rapid analysis and high sampling space resolution. In this research we improved the DEP system for more suitable in rapid analysis. We rule of the use of Syringe pump and its tube. Replace it by using solution tank so that we can save the time cost by disassemble syringe pump and tube when sampling. We also change the electric field by different high voltage applied mode for safety concern. In this study DEP/MS were used in plants analysis applications: capsaicin in peppers, systematic pesticide absorption in tomato and toxic compounds distribution in potato surface.