Development and Validation of HPLC-UV Method for Determination of Paraquat in Raw and Commercial Samples

A new, rapid, efficient, low cost, robust, accurate and reproducible analytical method for the determination of Paraquat has been developed using reverse phase high performance liquid chromatography with UV-Visible detector (HPLC-UV). Paraquat is a frequently used herbicide. This method is useful for the detection and quantification of paraquat in raw materials and commercial samples with excellent recoveries upto almost 100%. pH of the mobile phase (acetonitrile:methanol:water 1:1:2) was optimized as 2.5 with ortho-phosphoric acid. This analytical method was validated with excellent linearity R2 = 0.999. LOD and LOQ were calculated to be 0.74 mg/L and 2.45 mg/L, respectively. The method showed a high precision (RSD%) value of 0.32, while the accuracy measured in terms of percentage recovery was almost 100% under optimized conditions. The robustness of the method was studied by changing the flow rate and the mobile phase concentration ratios, and the results obtained were within the permissible accepted values.