2,3-Dimercapto-1-propanesulfonic acid

2,3-Dimercapto-1-propanesulfonic acid (abbreviated DMPS) or its sodium salt (known as Unithiol) are chelating agents that form complexes with various heavy metals. It is related to dimercaprol, which is another chelating agent.

The synthesis of DMPS was first reported in 1956 by scientists in the Soviet Union. The effects if DMPS on heavy metal poisoning, including with polonium-210 were investigated in the following years. DMPS was found to have some protective effect, prolonging the survival time.

A study was done of workers involved in the production of a calomel skin-bleaching lotion and in direct contact with mercurous chloride, who already showed elevated urine mercury levels. The sodium salt of (DMPS) was found to be effective in lowering the body burden of mercury and in decreasing the urinary mercury concentration to normal levels.