1. On-line sample preconcentration with chemical derivatization of bacterial biomarkers by capillary electrophoresis: a dual strategy for integrating sample pretreatment with chemical analysis.
- Author
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Ptolemy AS, Le Bihan M, and Britz-McKibbin P
- Subjects
- Acetylcysteine, Bacteria chemistry, Bacteriological Techniques instrumentation, Biomarkers analysis, Culture Media chemistry, Diaminopimelic Acid analysis, Escherichia coli chemistry, Escherichia coli isolation & purification, Escherichia coli metabolism, Hydrogen-Ion Concentration, Muramic Acids analysis, Stereoisomerism, o-Phthalaldehyde, Bacteria isolation & purification, Bacteriological Techniques methods, Electrophoresis, Capillary methods
- Abstract
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.
- Published
- 2005
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