High-performance liquid chromatographic method for the separation and quantitative estimation of anti-parasitic melaminophenyl arsenical compounds.

A sensitive high-performance liquid chromatographic method has been developed for the separation and quantitative estimation of melaminophenyl arsenical drugs used in the treatment of human and veterinary trypanosomiases. Five clinically relevant compounds (melarsoprol, melarsonyl potassium, cymelarsan, melarsen oxide, and sodium melarsen) can be separated with an octadecylsilane reverse-phase column and detected down to 10 pmol per injection. The chromatographic system utilizes a propanol gradient in water, with lithium camphor sulphonate as ion modifier, and detection by ultraviolet absorbance at 280 nm. Preliminary results indicate that the arsenical compounds can be extracted and concentrated from serum using octadecylsilane solid-phase extraction cartridges. This method represents the first specific and sensitive assay system for separating and quantitatively estimating this important class of antiparasitic agents.