Microfabricated Glow Discharge Plasma (MFGDP) for Ambient Desorption/Ionization Mass Spectrometry

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• 作者：Xuelu Ding ; Xuefang Zhan ; Xin Yuan ; Zhongjun Zhao ; Yixiang Duan
• 刊名：Analytical Chemistry
• 出版年：2013
• 出版时间：October 1, 2013
• 年：2013
• 卷：85
• 期：19
• 页码：9013-9020
• 全文大小：403K
• 年卷期：v.85,no.19(October 1, 2013)
• ISSN：1520-6882

文摘

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 掳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/mm² level. The relative standard deviation (RSD) of manual sampling ranged from 10% to 20%, while correlation coefficients of the working curve (R²) 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.