HPLC Determination of m-Aminobenzenesulfonic Acid and m-Nitrobenzenesulfonic Acid in the Preparation Process of m-Aminobenzenesulfonic Acid by Reduction of m-Nitrobenzenesulfonic Acid

A HPLC method was proposed for determination of m-aminobenzenesulfonic acid and m-nitrobenzenesulfonic acid in the preparation process of m-aminobenzenesulfonic acid from reduction of m-nitrobenzenesulfonic acid. The analytes were separated on a kromasil C18 (150 mm×4.6 mm, 5 μm) chromatographic column, with ammonium dihydrogen phosphate solution (0.10 mol·L-1) as mobile phase, and detected at the UV wavelength of 236 nm. The linear ranges of m-aminobenzenesulfonic acid and m-nitrobenzenesulfonic acid were 4.0×10-5-2.4×10-4mol·L-1 and 8.0×10-5-4.0×10-4mol·L-1 respectively, with detection limits (3S/N) of 1.5×10-6mol·L-1 and 3.5×10-6mol·L-1, and the lower limits of determination (10S/N) of 5.0×10-6, 1.0×10-5mol·L-1, respectively. Recovery rates obtained by standard addition method were between 95.3% and 102% and RSDs (n=6) were in the range of 0.86%-2.6%.