Application of tributyltin chloride to the separation and column chromatography of thiols

Tributyltin chloride (TBT) has the properties of a liquid anion exchanger with a special affinity for sulphydryl groups. Thiols such as cysteine can be separated by extraction from aqueous solution with organic solvents in the form of TBT mercaptides. The graphs of extraction coefficient verus pH have maxima whose positions depend on the nature of the thiols. Thiols can be separated from each other by using TBT on polyamide as the column packing and elution with buffers of gradually increasing or decreasing pH.