Extraction of Metronidazole and Furazolidone from industrial effluents by double salting out assisted liquid liquid extraction technique and their analyses by HPLC-UV method.

We have developed a new analytical method for simultaneous determination of Metronidazole and Furazolidone by High Performance Liquid Chromatography (HPLC). The method is coupled to double salting-out assisted liquid-liquid extraction (SALLE) which facilitates the detection and quantification of Metronidazole and Furazolidone in different dosage forms by subsequent HPLC analysis. Extraction parameters such as solvent, pH and salt concentration are optimized and liquid liquid extraction showed efficiency up to 102% and 100% for Metronidazole and Furazolidone respectively in chloroform, at pH 3 and low salt concentration (0.5g KCl and 0.5 gNaNO<inf>3</inf>). The designed simultaneous analytical method is further validated and Metronidazole and Furazolidone showed linearity upto R20.994 and 0.9936 respectively. LOD was 2.1μg/ml, 1.5μg/ml and LOQ was 21.1μg/ml, 15.2μg/ml for metronidazole benzoate and furazolidone. Precision of the method is 1.84% (RSD) and 1.72% (RSD) for Metronidazole and Furazolidine respectively. Moreover, accuracy is measured in terms of percent recovery which is more than 100% for both analytes under optimized conditions. Finally, robustness is evaluated by changing the flow rate and detection wavelength which is also obtained within permissible limit. This indicates that the proposed method is simple, efficient and shows excellent recoveries for simultaneous determination of Metronidazole and Furazolidone in different dosage forms and Industrial effluents.