Simultaneous evaluation of neonicotinoids in cotton seed cake using reverse phase high‐performance liquid chromatography

BACKGROUND: The cotton crop accounts for more than 52% of total insecticide usage in India. Neonicotinoids, being newer insecticides, have found greater use in the northern region. In this study a rapid and sensitive high‐performance liquid chromatography method was developed for measuring neonicotinoid residues in cotton seed cake (CSC). The method involves the extraction of three neonicotinoids from CSC with acetonitrile/water (80:20 v/v), followed by liquid–liquid partitioning and column clean‐up prior to injection. RESULTS: Recoveries at 0.5–2 µg g−1 spiking levels varied from 95.60 to 79.50% for imidacloprid, from 92.89 to 84.00% for acetamiprid and from 96.96 to 88.36% for thiacloprid. Minimum detectable levels using this method were 5, 10 and 20 ng g−1 for imidacloprid, acetamiprid and thiacloprid respectively. CONCLUSION: The method developed in this study allows rapid and reliable measurement of the insecticides imidacloprid, acetamiprid and thiacloprid in CSC.