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Study on diffusion behavior of analyte in an electrospray ionization source
Author(s) -
Gao Fang Yuan,
Zhang Ling Yi,
Li Xiu Qin,
Zhang Wei Bing,
Zhang Qing He
Publication year - 2016
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.7622
Subject(s) - chemistry , analyte , electrospray ionization , diffusion , analytical chemistry (journal) , electrospray , ionization , mass spectrometry , flow injection analysis , ion , phase (matter) , chromatography , detection limit , thermodynamics , physics , organic chemistry
Rationale Diffusion of an analyte is one of the main determinants of reduced sensitivity in an electrospray ionization (ESI) source. In this work, the relative responses of compounds and their stable isotope‐labeled (SIL) products in different injection modes were compared to investigate the diffusion behavior of analytes in ESI, without influence of other factors. Methods Chloramphenicol (CAP) and D 5 ‐CAP as well as melamine (Mel) and 13 C 3 ‐Mel were used to illustrate the diffusion behavior in different operation modes and different ion sources, by comparing their relative responses in infusion mode and flow injection analysis (FIA) mode under variable temperature. Results In infusion mode, sample solution was introduced by syringe, and formed a stable and continuous signal. While in FIA mode, because of the huge difference in volume between the sample solution and the mobile phase, it is assumed that analyte ionizes and transmits in the gaseous phase created by the mobile phase. Analytes formed different concentration distributions in the two injection modes. The relative responses of CAP and D 5 ‐CAP increased from 0.81 to 0.98 when the temperature was increased from 300 °C to 650 °C in infusion mode and decreased from 1.37 to 1.17 with increasing temperature in FIA mode. The opposite trends of the two injection modes were also obtained in positive operation modes and ion sources with different configuration. Conclusions Opposite variation tendencies of relative responses of model samples and their stable isotope‐labeled products with temperature were observed for infusion and FIA injection modes, indicating different diffusion behaviors in the two injection modes. These results provide a theoretical basis for ion source designing and better understanding of the ESI mechanism. Copyright © 2016 John Wiley & Sons, Ltd.