TRACE ANALYSIS IN HPLC

Simple and rapid methods were developed for the determination of trace levels of pyridine and ethanolamine in water samples. The methods uti lised the HPLC separation using precolumn on-line preconcentration. Th e limit of the determination of pyridine at the wavelength of 255 nm w as 50 ppt. The recovery of spiked tap water (at 1 ppb) was 90% and the recovery of spiked river water at the same concentration was 88%. The problem of ethanolamine preconcentration was solved by adding octane- 1-sulphonic acid (OSA) into the water sample and ion pair of ethanolam ine was sorbed in the precolumn C18. After the precolumn flushing the ion pair was introduced into analytical column with lower concentratio n of OSA in mobile phase. Electrochemical detection at +0.88 V was use d. The limit of the determination was about 2 ppb.