Sonic Spray Research Articles

Direct Coupling of Semi‐micro Liquid Chromatography and Sonic Spray Ionization Mass Spectrometry for Pesticide Analysis

Direct Coupling of Semi‐micro Liquid Chromatography and Sonic Spray Ionization Mass Spectrometry for Pesticide Analysis

Direct Coupling of Semi-micro Liquid Chromatography and Sonic Spray Ionization Mass Spectrometry for Pesticide Analysis

Direct Coupling of Semi-micro Liquid Chromatography and Sonic Spray Ionization Mass Spectrometry for Pesticide Analysis

Multiply-charged Ion Formation by Sonic Spray

In sonic spray ionization technique, a solution from a fused-silica capillary is sprayed with a sonic gas flow coaxial to the capillary. The current for the ions produced and for the charged droplets is found to be dramatically enhanced when a voltage is applied to a surrounding metal piece, which is isolated from the solution by the fused-silica capillary. This can be ascribed to the induced concentration difference between positive and negative ions in the solution near the surface. Furthermore, multiply-protonated molecules produced in this way from protein solutions are analyzed with a quadrupole mass spectrometer. The ion intensity shows a strong dependence on the voltage but the diameter of the droplet produced by the spray is likely to be independent of the voltage. Thus, we conclude that the charge density of the droplet is regulated by the voltage.

Recent Progress in Organic Analysis Using Liquid Chromatograph Mass Spectrometer (LC-MS).

Combined liquid chromatograph mass spectrometer (LC-MS) for organic micro analysis was described. The review of the historical aspect on the development LC-MS interface is important to understand recent advanced methods for the analysis. Several problems found in the earlier developed interface are stated. The moving belt interface was the first successful desolvation method. The simplified method, such as direct liquid introduction (DLI) as well as thermospray (TSP), are discussed. Fast atom bombardment (FAB) ionization is available in the frit interface. The compositions of various spray methods are presented for the LC-MS interface including particle beam (PB), electrospray (ES), atmospheric pressure chemical ionization (APCI), sonic spray, droplet electrospray and ionspray. Several applications using these interfaces are shown. Recent mass spectrometers using Fourier transform (FT) technique which exhibits high mass resolving power and accuracy is one of the best analyzer for LC-MS work. Dual ion source equipped with matrix assisted laser desorption ionization (MALDI) and external ionization source are commonly available for FTMS. The new topics on the recent developed mass spectrometry are introduced.

Sonic Spray Ionization Method for Atmospheric Pressure Ionization Mass Spectrometry

We have developed a novel spray ionization method for interfaces in capillary electrophoresis/mass spectrometry and liquid chromatography/mass spectrometry. This method is called sonic spray ionization. In this method it is not necessary to apply an electric field to the capillary of the ion source, which operates at room temperature. A solution in methanol and water from a fused-silica capillary is sprayed under atmospheric pressure with nitrogen gas flow coaxial to the capillary

Sonic spray of H2SO4 in a swirling heated air stream

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