Estimation of β-cyfluthrin and imidacloprid in okra fruits and soil by chromatography techniques

Dissipation of beta-cyfluthrin and imidacloprid in okra was studied following three applications of a combination formulation of Solomon 300 OD (beta-cyfluthrin 9 % + imidacloprid 21 %) @ 60 and 120 g a.i. ha(-1) at 7 days interval. Residues of beta-cyfluthrin and imidacloprid in okra were estimated by gas liquid chromatography (GLC) and high performance liquid chromatography (HPLC), respectively. Residues of beta-cyfluthrin were confirmed by gas chromatograph-mass spectrometry (GC-MS) and that of imidacloprid by high performance thin layer chromatography (HPTLC). Half-life periods for beta-cyfluthrin were found to be 0.91 and 0.68 days whereas for imidacloprid these values were observed to be 0.85 and 0.96 days at single and double the application rates, respectively. Residues of beta-cyfluthrin dissipated below its limit of quantification (LOQ) of 0.01 mg kg(-1) after 3 and 5 days at single and double the application dosage, respectively. Similarly, residues of imidacloprid took 5 and 7 days to reach LOQ of 0.01 mg kg(-1), at single and double dosages respectively. Soil samples collected after 15 days of the last application did not show the presence of beta-cyfluthrin and imidacloprid at their detection limit of 0.01 mg kg(-1).