Predicting ESI/MS Signal Change for Anions in Different Solvents

LC/ESI/MS
is a technique widely used for qualitative and quantitative
analysis in various fields. However, quantification is currently possible
only for compounds for which the standard substances are available,
as the ionization efficiency of different compounds in ESI source
differs by orders of magnitude. In this paper we present an approach
for quantitative LC/ESI/MS analysis without standard substances. This
approach relies on accurately predicting the ionization efficiencies
in ESI source based on a model, which uses physicochemical parameters
of analytes. Furthermore, the model has been made transferable between
different mobile phases and instrument setups by using a suitable
set of calibration compounds. This approach has been validated both
in flow injection and chromatographic mode with gradient elution.