Detection of flumethrin acaricide residues from honey and beeswax using high performance liquid chromatography (HPLC) technique

Abstract

Residues of acaricide, flumethrin were detected from honey and beeswax using high performance liquid chromatography (HPLC) technique. Forty samples of honey were collected before flumethrin treatment and 30, 60, and 90 days after application from five Apis mellifera colonies; one sample from the central frame containing brood and honey, while the other from the frame filled with honey from peripheral side of each colony at every sampling interval. Honey samples were taken by uncapping the cells with knife and extracting the honey with a syringe of 12 mL capacity. Twenty samples of beeswax (one sample from peripheral frames of each colony) were collected from five selected beehives. Two solvents n-hexane and dichloromethane (4:6, v/v) were used for making extracts of honey and beeswax samples, respectively which were further concentrated by rotary evaporation. All the samples were purified and detected at a wavelength of 267 nm. From the HPLC residual analysis, all the honey samples were found free of acaricide flumethrin; as it could not be detected from any of the 40 samples. However, all the beeswax samples were positive for flumethrin residues. The highest level of flumethrin (0.0759 mg/kg) was detected from the samples of beeswax samples taken from the bee colonies after 30 days of flumethrin application. Despite of the fact that flumethrin residues were detected from all the test beeswax samples, however no one was noticed to exceed the tolerance levels established by Environmental Protection Agency (EPA) and European Commission guidelines. Present method of flumethrin detection through HPLC also proved to be a promising alternative of Gas Chromatography with high sensitivity and can be used as an appropriate method to determine flumethrin residues from honey and beeswax.