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Development of high‐pressure probe electrospray ionization for aqueous solution
Author(s) -
Rahman Md. Matiur,
Chen Lee Chuin,
Hiraoka Kenzo
Publication year - 2012
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.6427
Subject(s) - chemistry , electrospray , electrospray ionization , aqueous solution , analytical chemistry (journal) , ionization , atmospheric pressure , corona discharge , ambient pressure , mass spectrometry , chromatography , ion , electrode , organic chemistry , geology , oceanography , physics , thermodynamics
RATIONALE Probe electrospray ionization (PESI) is a recently developed method that uses a sharp solid needle as electrospray emitter and the sample is loaded to the needle tip by repetitive movement of the needle probe. This method has been previously used for the analysis of sample with high salt concentration and real‐world samples without sample pretreatment. Although PESI is also applicable to aqueous solution, the ion signal stability and reproducibility were not satisfactory due to the spontaneous occurrence of corona discharge taking place on the metallic needle tip. METHODS In the previous version of PESI, the ionization was performed under an open environment, thus ambient condition such as humidity and the presence of environmental contaminant also affected the performance of PESI. In this paper, we report a modified version of PESI in which the electrospray and the desolvation of charged droplets are performed inside an enclosed chamber which is pressurized to >1 atm with dry air. RESULTS Under a super atmospheric condition, the dielectric strength of the ambient gas was enhanced and stable electrospray could to be initiated without the occurrence of corona discharge even for liquid sample with high surface tension such as pure water. A comparative study of atmospheric‐pressure PESI and high‐pressure PESI (HP‐PESI) had been performed to demonstrate the improvement of PESI in sensitivity and signal stability for the detection analytes in aqueous solution. CONCLUSIONS HP‐PESI offers a higher sensitivity and signal stability over PESI due to the absence of gaseous breakdown, better desolvation, and higher ion sampling rate by the mass spectrometer. Copyright © 2012 John Wiley & Sons, Ltd.