title: Direct Analysis of Nonvolatile Chemical Compounds on Surfaces Using a Hand-Held Mass Spectrometer with Synchronized Discharge Ionization Function.
abstract: Synchronized discharge ionization (SDI) was previously developed for hand-held mass spectrometers with discontinuous atmospheric pressure interfaces. The function of SDI has been demonstrated for analysis of volatile organic compounds in air at high sensitivity, which is attributed to the fact that ions were produced next to the ion trap mass analyzer inside the vacuum manifold. In this study, a simple sampling device was designed and fitted to a hand-held mass spectrometer to characterize its potential in direct analysis of low-volatility chemicals on surfaces. Nine chemicals of vapor pressures ranging from 10(-4) to 10(-8) Torr (at room temperature), including pesticides, illicit drugs, and explosives, were selected to evaluate and demonstrate the analytical capability of the designed system. Compounds of vapor pressures below 10(-7) Torr, such as tetryl, cocaine, and tetrahydrocannabinol (THC), have been successfully detected. Direct analysis of pesticides from fruit and explosives from a large surface area has also been demonstrated. Tandem mass analysis was performed, which helped to confirm the analyte identity as well as to improve the signal-to-noise ratio (S/N).
authors.affiliation: Weldon School of Biomedical Engineering, ‡Department of Electrical and Computer Engineering, and §Department of Chemistry, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Xiao
authors.initials: X
authors.lastname: Wang
authors.affiliation: Weldon School of Biomedical Engineering, ‡Department of Electrical and Computer Engineering, and §Department of Chemistry, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Weldon School of Biomedical Engineering, ‡Department of Electrical and Computer Engineering, and §Department of Chemistry, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Ouyang
mesh_terms: D000814:Aniline Compounds / Q000032:analysis*; D001274:Atmospheric Pressure; D005638:Fruit / Q000737:chemistry; D017736:Ion-Selective Electrodes; D027845:Malus / Q000737:chemistry; D013058:Mass Spectrometry / Q000295:instrumentation*; D009578:Nitrobenzenes / Q000032:analysis*; D013499:Surface Properties; D014303:Trinitrotoluene / Q000032:analysis*; D014835:Volatilization
chemical_list: D000814:Aniline Compounds; D009578:Nitrobenzenes; D014303:Trinitrotoluene; C015384:nitramine