Abstracto

Application of factorial design for optimization of flow-injection spectrophotometric determination of tetracycline in pharmaceutical formulations

Chinar Mohammed Risheed

A simple and rapid flow injection (FI) spectrophotometric procedure for the determination of tetracycline (TC) has been developed. The method is based on the injection of 150 ìl standard or sample solution into a distilled water stream which merged at the confluent point with ferric nitrate solution with the optimum flow rate of 1.5 mL/min, subsequently the reaction will occur inside the reactor coil, forming brown color product that monitored at 418 nm. The flowinjection experimental conditionswere optimized by means of full factorial design. Under the optimum conditions, calibration graphwas obtained over the range 2.0-120 ìg/ml with a detection limit of 1.0 ìg/ml. The correlation coefficient andmolar absorptivitywere 0.9994 and 4.343x103 L/mol.cmrespectively. The results showed a good precision and accuracy. The method was successfully applied to the determination of tetracycline in pharmaceutical formulations and showed good agreement with those obtained by the standard method at 95%confidence level, with a sample throughput of 60/h.