High-Performance Liquid Chromatographic Analysis of Trace Amounts of Carboxylic Acids in Environmental Water after Preconcentration with a Chemically-Modified Sephadex G10

A chemically-modified Sephadex G10, on which a stearyl group and a quaternary ammonium base are introduced, was developed as a new adsorbent for carboxylic acids, and was applied to their separation analysis by using reversed-phase high-performance liquid chromatography (HPLC). Almost all carboxylic acids were quantitatively adsorbed on the chemically-modified Sephadex G10 at pH 8 without any interference from other inorganic ions included in environmental samples. Elution of the adsorbed carboxylic acids from the chemically-modified Sephadex G10 was easily accomplished using a dilute hydrochloric acid solution. A separation analysis by reversed-phase HPLC for preconcentrated carboxylic acids in environmental water was attained using an in-line color reaction for the carboxylic acids. The determination limits were 10-7M for a 100ml sample volume. The relative standard deviations were less than 2%.