The role of polar solvents in the injection samples in ion-pair reversed-phase partition high performance liquid chromatography has been investigated by using metal chelates with 2,2′-dihydroxyazobenzene and 4-(2-pyridylazo)resorcinol. When the chelates were separated on C18-bonded silica packing with an aqueous methanol mobile phase containing tetrabutylammonium bromide and detected spectrophotometrically, the peak profile was significantly distorted by the organic solvent in the sample solution. When a solvent having a polarity greater than the mobile phase was used for injection, the peaks were better resolved and sharpened. The best peak profile, assessed by peak height and resolution, was obtained with aqueous sample injection. An interpretation of this phenomenon is given based on the concentration process of analytes at the top of the column.
|Number of pages||8|
|Journal||Solvent Extraction Research and Development|
|Publication status||Published - 1998 Dec 1|
ASJC Scopus subject areas
- Chemical Engineering(all)