Disappearance and hazard quotient of chlorpyrifos-methyl, fipronil, and imidacloprid insecticides from dates

Abstract

Control strategies of red palm weevil (RPW) mainly depend on the use of insecticides. However, the residue of insecticides in dates might cause poisoning risk to the consumers. Therefore, the present study aimed to measure the disappearance rates of the extensively applied insecticides on date palm trees. Residues of chlorpyrifos-methyl (CPM), fipronil (FIP), and imidacloprid (IMD) insecticides in and/or on dates were extracted and cleaned-up using the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. The residues of CPM, FIP, and IMD were determined by GC-FPD, GC-ECD, and HPLC, respectively. Recoveries of CPM, FIP, and IMD ranged from 86.3 to 98.2%. CPM on dates degraded faster than FIP and IMD. However, after 21 days of the last spray application, 74, 50, and 67% of CPM, FIP, and IMD disappeared, respectively. Residues of CPM and IMD insecticides posed no risk quotient, but FIP caused a risk to humans, depending on the consumption pattern of dates. Insecticides with a fast degradation pattern should be incorporated into the management strategy of RPW to reduce the amount on residues in dates.