PRECOLUMN DERIVATIZATION FOR IMPROVED DETECTION IN LIQUID CHROMATOGRAPHY-PHOTOLYSIS-ELECTROCHEMISTRY

Precolumn, homogeneous chemical derivatization with Sanger's reagent (2,4-dinitrofluorobenzene) is utilized to improve the chromatographic and detection properties of amino alcohols and amino acids. The 2,4-dinitrophenyl derivatives are separated using reversed-phase liquid chromatography and are detected using the hybrid photolysis-electrochemical (hv-EC) detector in tandem with UV absorbance detection. Following optimization of reaction, chromatographic, and detection variables, the derivatization-detection approach provides limits of detection in the low parts-per-billion range, with a linearity of roughly three orders of magnitude.