Premium
Online Sample Concentration in Partial‐Filling Chiral Electrokinetic Chromatography – Mass Spectrometry
Author(s) -
Wuethrich Alain,
Haddad Paul R.,
Quirino Joselito P.
Publication year - 2014
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.22257
Subject(s) - chemistry , chromatography , ammonium acetate , mass spectrometry , capillary electrophoresis , analyte , detection limit , ammonium formate , electrospray , electrospray ionization , analytical chemistry (journal) , acetonitrile , dilution , enantiomer , high performance liquid chromatography , organic chemistry , physics , thermodynamics
The concentration sensitivity of a racemic drug (chlorpheniramine maleate) in chiral capillary electrophoresis with electrospray ionization – mass spectrometric detection was improved ~500‐fold via stacking. Enantiomeric separation was achieved through the use of a neutral chiral pseudostationary phase (2‐hydroxpropyl‐β‐cyclodextrin), untreated fused‐silica capillaries, and the application of a partial‐filling technique to prevent the pseudostationary phase from entering the detector. A concentration factor of 50 resulted from field‐enhanced sample injection (FESI). However, the higher concentration factor was achieved by combining FESI with micelle‐to‐solvent stacking (MSS) to increase sample load and focus the analyte band. MSS was achieved by injection of an ammonium lauryl sulfate micellar plug prior to sample injection. The sample diluent was a 20‐fold dilution of the background electrolyte (50 mM ammonium acetate, pH 3.5) with 60% acetonitrile. This methodology provided a limit of detection (LOD) of as low as 5 ng/ml of the racemate. Chirality 26:734–738, 2013 . © 2013 Wiley Periodicals, Inc.