title: Microfabricated glow discharge plasma (MFGDP) for ambient desorption/ionization mass spectrometry.
abstract: A novel ambient ionization technique for mass spectrometry, microfabricated glow discharge plasma (MFGDP), is reported. This device is made of a millimeter-sized ceramic cavity with two platinum electrodes positioned face-to-face. He or Ar plasma can be generated by a direct current voltage of several hundreds of volts requiring a total power below 4 W. The thermal plume temperature of the He plasma was measured and found to be between 25 and 80 °C at a normal discharge current. Gaseous, liquid, creamy, and solid samples with molecular weights up to 1.5 kDa could be examined in both positive and negative mode, giving limits of detection (LOD) at or below the fg/mm(2) level. The relative standard deviation (RSD) of manual sampling ranged from 10% to ~20%, while correlation coefficients of the working curve (R(2)) are all above 0.98 with the addition of internal standards. The ionization mechanisms are examed via both optical and mass spectrometry. Due to the low temperature characteristics of the microplasma, nonthermal momentum desorption is considered to dominate the desorption process.
authors.affiliation: Research Center of Analytical Instrumentation, Analytical Testing Center and College of Chemistry, Sichuan University , Chengdu 610065, China.
authors.forename: Xuelu
authors.initials: X
authors.lastname: Ding
authors.forename: Xuefang
authors.initials: X
authors.lastname: Zhan
authors.forename: Xin
authors.initials: X
authors.lastname: Yuan
authors.forename: Zhongjun
authors.initials: Z
authors.lastname: Zhao
authors.forename: Yixiang
authors.initials: Y
authors.lastname: Duan
mesh_terms: D001128:Argon / Q000737:chemistry; D006371:Helium / Q000737:chemistry; D015394:Molecular Structure; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation / Q000379:methods*; D013696:Temperature
chemical_list: D006371:Helium; D001128:Argon