Determination of aliphatic amines in water using derivatization with fluorescein isothiocyanate and capillary electrophoresis laser-induced fluorescence detection

Detection-oriented derivatization of aliphatic amines and amine functional groups in compounds of environmental interest was studied using fluorescein isothiocyanate (FITC) with separation/determination by capillary electrophoresis/laser-induced fluorescence. Determinative levels down to 10 ppb were studied in deionized and environmental waters. Practical detection limits of 30 to 100 ppb or more were realized, depending on analyte and water source. Criteria were developed to compare results to desired performance in a derivatization method. FITC was judged to be a moderately successful reagent with drawbacks including extensive by-products, lack of specificity to analyte class, requirement to study each potential analyte carefully, and derivatization limits near 30 ppb. Advantages include low cost of reagent, ease in handling, and synthesis of an ionized derivative for free zone electrophoresis.