Effect of pH on Persistence and Degradation of Cyantraniliprole in Aqueous Media

The persistence and degradation of cyantraniliprole in water has been reported at six different pH values viz. 2, 4, 6, 7, 9.2 and 10. Water samples of different pH were fortified with standard solution of cyantraniliprole at 10 mgL⁻¹ and kept at 25±2°C. Cyantraniliprole and its two metabolites IN-J9Z38 and IN-JCZ38 were monitored using HPLC-PDA. Calibration curves in the concentration range 0.001–10 mgL⁻¹ were found to be linear for all the three analytes with coefficient of determination R²> 0.991. Recoveries of cyantraniliprole, IN-J9Z38 and IN-JCZ38 from water at 0.05, 0.01 and 0.005 mgL⁻¹ fortification levels were in the range of 89.79–93.66 per cent with relative standard deviation of 2.19–5.16 per cent Limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.001 and 0.005 mgL⁻¹ at 3:1 and 10:1 signal to noise ratio, respectively. Half-life of cyantraniliprole in different pH solutions ranged from 2.8 to 99.0 d. Cyantraniliprole was found to be highly persistent in acidic solutions (pH 2 and 4). In alkaline solutions (pH 9.2 and 10), it degraded very fast with the formation of IN-J9Z38 as its major metabolite.