Chemiluminescence flow-through sensor for pipemidic acid using solid sodium bismuthate as an oxidant Original Research Article

A novel chemiluminscence (CL) flow-through sensor for pipemidic acid is described. It was based on the sensitizing effect of pipemidic acid on the CL oxidation of sulfite by sodium bismuthate in H2SO4 media. The solid-phase sodium bismuthate was mechanicially immobilized on the sponge rubber inside of the CL flow cell as CL oxidant. The calibration graph is linear in the range 0.1–10 μg/ml with a detection limit of 6.2×10−8 g/ml (3σ). A complete analysis could be performed in 1 min with a relative standard deviation (R.S.D.) of 2.5% for 2 μg/ml pipemidic acid (n=8). This method has been successfully applied to determine pipemidic acid in pharmaceutical preparation.