کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1193570 1492378 2007 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Influence of needle voltage on the formation of negative core ions using atmospheric pressure corona discharge in air
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Influence of needle voltage on the formation of negative core ions using atmospheric pressure corona discharge in air
چکیده انگلیسی

The dependence of the formation of negative core ions Y− and their hydrated cluster ions Y−(H2O)n on needle voltage has been examined by using atmospheric pressure corona discharge ionization mass spectrometry. An insect pin (200 μm in diameter, 20 mm in length, and ca. 1 μm in the tip radius) was used as the corona needle. At the lowest effective needle voltage (−1.9 kV), water cluster ions OH−(H2O)n with a core ion OH− were observed. Furthermore there was a discontinuity between the abundances of OH−(H2O)3 at m/z 71 and OH−(H2O)4 at m/z 89, suggesting that the cluster OH−(H2O)3 is more stable than OH−(H2O)4. The ion OH−(H2O)3 which may be referred to as “the first hydrated shell” is formed via hydration of the core ion OH− in air. Various different core ions Y− appeared as the hydrated cluster ions Y−(H2O)n with increasing needle voltage. At relatively low voltage (−2.3 kV), the dominant hydrated clusters observed were OH−(H2O)n and O2H−(H2O)n. At the highest corona voltage (−3.5 kV), the well-known long-lived core ion NO3− and its hydrated clusters NO3−(H2O)n were mainly observed. The resulting negative core ions OH−, NO2−, NO3−, HNO3−, CO3−, and CO4−, which are atmospherically important ions or stable terminal ion species in tropospheric atmosphere, are discussed from the standpoint of ion evolution in air.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Mass Spectrometry - Volume 261, Issue 1, 1 March 2007, Pages 38–44
نویسندگان
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