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On‐line sample preconcentration with chemical derivatization of bacterial biomarkers by capillary electrophoresis: A dual strategy for integrating sample pretreatment with chemical analysis
Author(s) -
Ptolemy Adam S.,
Le Bihan Marianne,
BritzMcKibbin Philip
Publication year - 2005
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200500278
Subject(s) - derivatization , muramic acid , chromatography , chemistry , capillary electrophoresis , diaminopimelic acid , sample preparation , amino sugar , amino acid , high performance liquid chromatography , biochemistry , peptidoglycan , cell wall
Simple, selective yet sensitive methods to quantify low‐abundance bacterial biomarkers derived from complex samples are required in clinical, biological, and environmental applications. In this report, a new strategy to integrate sample pretreatment with chemical analysis is investigated using on‐line preconcentration with chemical derivatization by CE and UV detection. Single‐step enantioselective analysis of muramic acid (MA) and diaminopimelic acid (DAP) was achieved by CE via sample enrichment by dynamic pH junction with ortho ‐phthalaldehyde/ N ‐acetyl‐ L ‐cysteine labeling directly in‐capillary. The optimized method resulted in up to a 100‐fold enhancement in concentration sensitivity compared to conventional off‐line derivatization procedures. The method was also applied toward the detection of micromolar levels of MA and DAP excreted in the extracellular medium of Escherichia coli bacterial cell cultures. On‐line preconcentration with chemical derivatization by CE represents a unique approach for conducting rapid, sensitive, and high‐throughput analyses of other classes of amino acid and amino sugar metabolites with reduced sample handling, where the capillary functions simultaneously as a concentrator, microreactor, and chiral selector.