QuEChERS technique was validated and measurement uncertainty determined for residue analysis of fipronil and imidacloprid on chilli. LOQ of fipronil and imidacloprid was 0.001 and 0.05 mg kg-1, respectively. Pesticide was applied as foliar spray at the recommended (50 + 50 g ai ha-1) and double the recommended dose (100 + 100 g ai ha-1), and drenching of soil @ 200 + 200 and 400 + 400 g ai ha-1, respectively. Residues of fipronil and imidacloprid were estimated using GC and HPLC, respectively. Following foliar application, initial residues of fipronil and imidacloprid in chilli were 0.498 and 0.993 mg kg-1 and 0.505 and 1.007 mg kg-1, at recommend and double dose, respectively. Drenching resulted in initial residues of 0.097 and 0.136 mg kg-1 for fipronil and 0.280 and 0.443 mg kg-1 for imidacloprid at recommend and double dose, respectively in fruits on 3rd day of treatment.
Sharma et al. (Sun,) studied this question.