nitromersol, synthetic mercury-containing organic compound used as an antiseptic for the skin and mucous membranes and as a disinfectant for sterilizing surgical instruments. It is related to merbromin (Mercurochrome) and thimerosal (Merthiolate). Nitromersol disinfects by the action of the mercury in the molecule, which disrupts the enzymatic metabolism of the microorganism. It occurs as a yellowish powder or granules, soluble in alkaline solutions. It is used as a 0.5 percent alcoholic tincture or as a 0.2 percent aqueous solution.