New approach for the on-line turbidimetric determination of metronidazole in pharmaceutical preparation via the use of a new homemade Ayah 6SX1-T-2D Solar-continuous flow injection analyser


A newly developed analytical method characterized by its speed and sensitivity for the determination of metronidazole (MZ) in pure and pharmaceutical preparation via turbidimetric measurement (0-180o) by Ayah 6SX1-T-2D Solar-CFI analyser. The method was based upon the formation of greenish yellow precipitate for ion pair compound for the reaction of phosphomolybdic acid with metronidazole in aqueous medium. Turbidity was measured via the reflection of incident light that collides on the surface precipitated particals at 0-180o. Chemical and physical parameters were investigated. Linear dynamic of metronidazole is ranged from 0.05-8 mmol.L-1,with correlation coefficient r = 0.9821 . The limit of detection (S/N= 3 )(3SB)=171.15 ng/sample from the step wise dilution for the minimum concentration in the linear dynamic ranged of the calibration graph with RSD% lower than 0.5% for 4, 4.5 mmol.L-1 (n=5) concentration of metronidazole. The method was applied successfully for the determination of metronidazole in three pharmaceutical drugs. A comparison was made between the newly developed method analysis with the classical method (HANNA instrument for turbidity measurement) using the standard addition method via the use of t-test. It was noticed that there was no significant difference between two methods at 95 % confidence level.