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Correction of the deviations in the retention times with Chromolith columns associated to the flow rate: Implications in the modelling of the retention behaviour
Author(s) -
PousTorres Sandra,
TorresLapasió José Ramón,
RuizÁngel María José,
GarcíaÁlvarezCoque María Celia
Publication year - 2011
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.201000647
Subject(s) - volumetric flow rate , chemistry , retention time , chromatography , analytical chemistry (journal) , flow (mathematics) , retention rate , data retention , volume (thermodynamics) , logarithm , work (physics) , column (typography) , mathematics , thermodynamics , materials science , mechanics , physics , computer science , mathematical analysis , geometry , connection (principal bundle) , computer security , optoelectronics
In a previous work ( J. Sep. Sci. 2009, 32 , 2793–2803), we reported an interpretive optimisation approach to achieve maximal resolution in minimal analysis time, based on models describing the retention and peak shape as a function of mobile phase composition and flow rate. The method was applied to the separation of a group of basic drugs in a Chromolith column. In that work, we found that the retention factors were sensitive to the flow rate. The reason of the observed deviations in retention times is the increase in the column volume at the applied pressure, which decreases the linear velocity inside the column. This behaviour forced to include a correction term in the model that described the retention. We show here how the deviations in retention times can be evaluated, allowing retention models that do not include the flow rate as a variable, similar to isocratic chromatography at fixed flow rate. The logarithm of the deviations in the retention times with flow rate is shown to correlate with the solute polarity. This correlation is compared with similar correlations for the retention factor at fixed mobile phase composition and the extrapolated retention factor in water at fixed flow rate.