Flow-injection with chemiluminescence detection for the determination of iproniazid Original Research Article

A new FIA — direct chemiluminescence method is proposed for the determination of iproniazid phosphate, based upon the oxidation of the drug by cerium(IV) in sulfuric acid medium at room temperature in presence of sulfite. The calibration graph is linear over the range 0.1–4.0 ppm of iproniazid phosphate, with a rsd (n=50, 1.0 mg l−1) of 3.1%, LOD (s/n=2) of 3 μg l−1 and sample throughput of 121 h−1. The influence of different foreign compounds (soluble starch, lactose, sodium saccharine, sucrose, glucose, sodium chloride, and isoniazid) which can be found accompanying iproniazid phosphate in pharmaceutical preparations is tested, no serious interferences are observed. The method is applied to determination of iproniazid phosphate in a synthetic sample (1.0 mg l−1 of iproniazid phosphate, three replicates) as well as in human urine (0.5 mg l −1 of iproniazid phosphate, three replicates). The obtained mean relative errors are of +0.17 and +0.66%, for the synthetic sample and urine sample, respectively.