Chemiluminescence determination of sodium 2-mercaptoethane sulfonate by flow injection analysis using cerium(IV) sensitized by quinine

A flow injection method with chemiluminescence (CL) detection is proposed for the determination of sodium 2-mercaptoethane sulfonate (MESNA), a drug often used to reduce the urotoxic effects of antineoplastic alkylating agents. The procedure is based on the reaction of the thiol with Ce(IV) in a sulfuric acid medium and measurement of the CL intensity produced by quinine used as a sensitizer. The optimum conditions for CL emission were investigated. Using the CL peak height as the analytical parameter, MESNA was determined over the concentration range 0.29–2.21 ng (1.97–9.85 μg·l⁻¹) with a detection limit of 0.21 ng (1.38 μg·l⁻¹) and a relative standard deviation (R.S.D.) of 4.1%. The method was applied satisfactorily to the determination of MESNA in pharmaceutical preparations with percentages of recovery between 94 and 105.