Potential of XXXX and @entity37409 in nonaqueous capillary electrophoresis coupled to electrospray ionization mass spectrometry. Application to the analysis of beta-blockers.

@entity15544 @entity37410 @entity37409 @entity1042 @entity27390 @entity1626 @entity2716 @entity15 @entity5189
A nonaqueous capillary electrophoresis (NACE) method, coupled with either UV or electrospray mass spectrometry (ESI- @entity15 ), is described for the simultaneous analysis of seven beta-blockers. The same electrolyte, namely 25 mM @entity5189 and 1 M @entity5189 , was used with different investigated organic solvents. In addition to frequently used organic solvents such as @entity1042 ( @entity2716 ) and @entity1626 ( @entity15544 ), @entity27390 and its derivatives were investigated. @entity27390 (FA) and @entity37409 ( @entity37410 ) present several interesting physico-chemical properties, one of them being a high dielectric constant (e). Since FA and NMF possess a high UV cutoff, beta-blockers with an absorbance above 250 nm were selected as model compounds in order to compare NACE-UV and NACE- @entity15 performances. FA and NMF showed different selectivity compared to water, @entity2716 or @entity15544 , and also demonstrated a higher efficiency in terms of the number of theoretical plates (especially NMF). To overcome their unfavorable optical properties, hyphenation with @entity15 detection appears as a promising technique, thanks to its benefits in terms of selectivity, sensitivity and universality. The practical compatibility of FA and NMF with ESI- @entity15 detection in combination with a sheath liquid configuration was demonstrated. In comparison to UV detection, sensitivity was increased, while a high efficiency was maintained. In addition, the low and stable generated currents observed were evidences for the successful hyphenation with ESI- @entity15 . Hence, FA and NMF seemed to be promising alternatives in NACE-ESI- @entity15 , either used as pure organic solvent or as a mixture with @entity2716 or @entity15544 .
