Thin-layer polarographic detector for the high-performance liquid chromatographic detection of thiourea derivatives

A polarographic thin-layer detector for high-performance liquid chromatography, was devised. The detector has a sandwich structure with a working surface area of the mercury electrode of 0.25 mm2. The detector was applied to the direct amperometric detection and for detection with reactivation of the electrode surface by voltage pulses. It is shown that the latter detection mode is suitable for the determination of compounds that form insoluble or complex mercury salts, e.g., thiourea. Thiourea and its derivatives can be separated and determined in a wide concentration range and the detection limit for thiourea corresponds to 2 ng injected. Thiourea can be determined directly in urine.