The research involved a rapid, automated and highly accurate developed CFIA/MZ technique for estimation of phenylephrine hydrochloride (PHE) in pure, dosage forms and biological sample. This method is based on oxidative coupling reaction of 2,4-dinitrophenylhydrazine (DNPH) with PHE in existence of sodium periodate as oxidizing agent in alkaline medium to form a red colored product at ʎmax )520 nm (. A flow rate of 4.3 mL.min-1 using distilled water as a carrier, the method of FIA proved to be as a sensitive and economic analytical tool for estimation of PHE.
Within the concentration range of 5-300 μg.mL-1, a calibration curve was rectilinear, where the detection limit was 3.252 μg.mL-1, and the RSD% was 4.09. Recovery was 100.55% with a sample throughput of 62 sample/hr. The proposed method was successfully applied for determining PHE in serum samples and pharmaceutical formulations, the interference of excipients was studied. The mechanism of the chemical reaction has been proposed. When the suggested method's results were compared to those provided by a British Pharmacopeia reference method, there was no discernible difference between the two at the 95 percent confidence level.
