Laboratory persistence study of bispyribac-sodium in acidic, neutral and basic water

Laboratory persistence studies were performed in water at pH 4.0, 7.0, and 9.0 using bispyribac-sodium 40% SC (w/v) formulation at the rates of T0 – Untreated Control, 1.0 (T1) and 2.0 (T2) µg/mL. The different pH Waters samples have been kept under sunlight. The sampling occasions are Acidic water: 0, 5, 10, 20 and 50 days for acidic water (pH 4.0), basic and Neutral water: 0, 5, 10, 20, 50, 70 and 90 days Samples collected on different occasions were analysed for Bispyribac-sodium content by a validated HPLC method. The average percent recovery for Bispyribac-sodium was 86.33% ± 1.74, 87.50% ± 1.20 and 89.0% ± 1.23 at 0.05 µg/mL and 91.33% ± 1.33, 93.0% ± 1.67 and 94.83% ± 1.82 at 0.5 µg/mL fortification level for acidic, neutral and basic water respectively. The method has a limit of quantification (LOQ) 0.05 µg/mL. The DT50 (Half Life) of bispyribac-sodium calculated by regression analysis from the dissipation data.