A rapid quantification method for simultaneous determination of pendimethalin and metribuzin contents in suspoemulsion formulation.

Abstract

Pendimethalin and metribuzin are combined to a suspoemulsion (SE) formulation that is treated as a pre-emergence and early post emergence herbicide. A simple reverse phase high performance liquid chromatography (RP-HPLC) method has been validated and applied for the simultaneous analysis of metribuzin and pendimethalin contents in suspoemulsion formulation. The mobile phase for the method was acetonitrile: water (65:35v/v) at a flow rate of 1.0 mL/min, and quantification was accomplished at 237 nm. Hypersil ODS column was used for the method's development and validation. Metribuzin's and pendimethalin's RTs were found to be 3.6 and 11.9 min, respectively. The limit of detection was 0.03 mg/l and 0.04 mg/l for Metribuzin and Pendimethalin respectively. The limit of quantification values was 0.09 mg/l for metribuzin and pendimethalin. The linearity of proposed method was investigated in the range of 2.51 to 100.54 mg/l (r2 = 99997) and 0.25 to 9.80 mg/l (r2 = 99997) for Pendimethalin and Metribuzin respectively. The percentage recovery found to be in range from 99.8 to 100.1 % and 99.8 to 100.3 for Pendimethalin and Metribuzin respectively. The percentage RSD values for intraday precision study and inter-day precision study were < 2.22 and < 1.57 for Metribuzin and Pendimethalin respectively as per modified Horwitz equation as requirements by SANCO. The method's performance was validated in terms of selectivity, specificity, precision, linearity, accuracy, LOD, LOQ, and robustness, according to SANCO guidelines. In this study, for the first time, an easy and speedy reverse phase high performance liquid chromatography approach for the simultaneous analysis of pendimethalin and metribuzin in SE formulation is presented.