cyhalothrin and flumethrin

A method for detection of flumethrin residue in honey by high-performance liquid chromatography was established. After n-hexane-dichloromethane (4:6, vol/vol) extraction, the honey samples were concentrated by rotary evaporation, purified by an Oasis HLB solid-phase extraction column, and detected using a UV detector at 267 nm. The interference of the matrix was greatly reduced by optimizing pretreatment conditions; thus, the minimal detection limit of cyhalothrin was 0.005 mg/kg, the average recovery was 80.8 to 96.8%, and the coefficient of variation was 0.6 to 1.5%. The precision and reproducibility of this method was suitable and applicable for detecting flumethrin residue in honey. With this method, 135 honey samples from seven locations in the People's Republic of China were tested; 77 samples tested positive for flumethrin residue, resulting in a detection rate of 75.3%. Samples from the Guangdong province had the highest flumethrin residue level (0.122 mg/kg) of the locations tested. On the basis of analytical validation, the high-performance liquid chromatography has been shown to be a promising alternative for the analysis of flumethrin residue in honey samples.

Topics: Animals; Beekeeping; China; Chromatography, High Pressure Liquid; Honey; Nitriles; Pesticide Residues; Pyrethrins; Reproducibility of Results; Solid Phase Extraction

A procedure to determine residue concentrations of synthetic pyrethroid insecticides (flumethrin, deltamethrin, cypermethrin and cyhalothrin) in the milk and blood of lactating dairy cows was developed. Extraction was performed with acetoritrile, n-hexane partitioning, and silica gel column cleanup with n-hexane and diethyl ether. Analysis was carried out by high-performance liquid chromatography and ultraviolet detection. Recovery of the four pyrethroids averaged 78 to 91% with a minimum detectable concentration of 0.001 mg/kg. The method was reproducible and sensitive.

Topics: Animals; Cattle; Chromatography, High Pressure Liquid; Female; Insecticides; Lactation; Milk; Nitriles; Pesticide Residues; Pyrethrins; Reproducibility of Results; Sensitivity and Specificity; Spectrophotometry, Ultraviolet