Simultaneous determination of bromoxynil and MCPA in commercial samples and raw materials using reversed phase high performance liquid chromatography.

This study encompasses a quick, efficient, repeatable and reproducible analytical method for simultaneous determination of Bromoxynil (3, 5-Dibromo-4-hydroxybenzonitrile) and MCPA (2-methyl-4-chlorophenoxyacetic acid) using RP-HPLC with UV-Detector. Bromoxynil + MCPA is one of the most selective post emergent herbicide formulations for the control of important broad leaf weeds infesting small grains (wheat, barley, oats, rye), conservation reserve program areas and grass grown for seed. Optimum weed control is achieved when Bromoxynil + MCPA is applied to actively growing weed seedlings. So, a simple, repeatable, reproducible and efficient simultaneous analytical method was developed for Bromoxynil + MCPA. The developed method was applied for the detection and quantitation of these pesticides in formulations and raw materials with excellent recoveries. It was validated according to ICH Guidelines with excellent linearity R2  = 0.992 for Bromoxynil and 0.998 for MCPA. For Bromoxynil, LOD = 1.57 mg/L and LOQ = 5.22 mg/L while for MCPA the LOD = 1.08 mg/L and LOQ = 3.62 mg/L was found. The proposed method has shown high precision (RSD %) 0.06% and 0.11% for Bromoxynil and MCPA respectively while the trueness has been calculated in terms of recovery percentage obtained as "mean value of Bromoxynil 99.53% and MCPA 100.10%" which is excellent under optimized conditions. For repeatability and reproducibility, five replicate readings of standard and sample were taken and had found within acceptable limits of relative standard deviation (RSD ≤  ± 2%). Finally, the robustness of the developed method was determined by changing flow rate and mobile phase ratios that has found within the permissible limits (% RSD NMT 1.5). So, the proposed analytical method has found to be more precise, valid and accurate at commercial scale.