Thin-layer chromatographic separation and determination of dibutylphosphoric acid in a mixture of monobutylphosphoric acid and tributyl phosphate

Abstract

A thin-layer chromatographic (TLC) technique using a silica gel-cellullose plate has been developed for the separation of a mixture of monobutylphosphoric acid (H₂MBP), dibutylphosphoric acid (HDBP) and tributyl phosphate (TBP) and for the determination of HDBP. The technique involves initial separation on a TLC plate followed by the determination of isolated HDBP by an indirect spectrophotometric method whereby the concentration of HDBP is measured by its ability to reduce the colour intensity of a thorium-thoron complex at 545 nm. Less than 1 µg of H₂MBP and HDBP can be detected on the TLC plate. The method is suitable for the determination of 40–260 µg of HDBP.