EFFECT OF COLUMN TEMPERATURE ON SEPARATION AND DETERMINATION OF DITHIOCARBAMATE CHELATES BY REVERSED-PHASE HPLC

The effects of column temperature on the separation and determination of tetramethylenedithiocarbamate (TMDC) and hexamethylenedithiocarbamate (HMDC) chelates have been studied at temperatures of 10° to 50°C by using reversed- phase high-performance liquid chromatography (HPLC). In general, dithiocarbamate chelates are unstable and decompose in reversed-phase columns, particularly at elevated temperatures. However, it is possible to stabilize the chelates by addition of free ligand to the eluent. Dithiocarbamate chelates of Cd, Ni, Pb, Cu, Hg, Co, and Bi have been separated on two C18 columns with methanol-water-chloroform eluents of varying ligand concentrations: 0, 1, 2, 5, 10, 20, and 50 p, M. Although the TMDC and HMDC chelates are stable at lower column temperatures, elevated temperatures are preferable in terms of column efficiency (separation time), detection limit (linear range of calibration curves), and reproducibility. © Oxford University Press 1992.