A capillary electrophoresis system with dual capacitively coupled contactless conductivity detection and electrospray ionization tandem mass spectrometry |
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Authors: | Kelliton José Mendonça Francisco Claudimir Lucio do Lago |
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Institution: | Department of Fundamental Chemistry, Institute of Chemistry, University of S?o Paulo, S?o Paulo – SP, CEP, Brazil |
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Abstract: | A commercial system that is comprised of a CE coupled to an ESI triple quadrupole mass spectrometer was equipped with two capacitively coupled contactless conductivity detectors (C4Ds). The first C4D was positioned inside the original cartridge, and the second C4D was positioned as close as possible to the ESI probe entrance by using a 3D‐printed support. The C4Ds electropherograms were matched to the ESI‐MS electropherogram by correcting their timescales by the factor LT/LD, where LT and LD are the total capillary length and the length until the C4D, respectively. A general approach for method development supporting the simultaneous conductivity and MS detection is discussed, while application examples are introduced. These examples include the use of C4D as a simple device that dismiss the use of an EOF marker, a low‐selectivity detector that continuously provide information about unexpected features of the sample, and even a detector that can be more sensitive than ESI‐MS. The C4D used in this setup proved to have a smaller contribution to the peak broadening than ESI‐MS, which allowed that a C4D, positioned at 12 cm from the inlet of an 80‐cm‐long capillary, could be used to foresee position and shape of the peaks being formed 6.8 times slower at the ESI‐MS electropherogram. |
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Keywords: | Conductivity detection Electrospray ionization Mass spectrometry |
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