ABSTRACT
Shell eggs sampled at retail outlets in two large Italian cities were tested to assess their freshness, food safety and the presence of veterinary drug residues. Some samples were found to be irregular due to lack of compliance with freshness requirements or shells were tainted by micro-cracks and foreign material. The most severe case of non-compliance was due to the presence of veterinary drug residues that either exceeded either the maximum acceptable residue limits or drugs that were prohibited.
ABSTRACT
A method to determine residues of the insecticide rotenone in honey using high-performance liquid chromatography (HPLC) is described. The sample was extracted with an acetone/water mixture, followed by a liquid/liquid partition with diethyl ether. A solid-phase extraction (SPE) clean-up step on alumina neutral cartridge was then performed. The chromatographic analysis was conducted on a C18 column (250 x 4 mm, 5 microm) using acetonitrile-water (65:35, v/v) as mobile phase. Rotenone was detected in the ultraviolet range at a wavelength of 295 nm. The specificity of the method was demonstrated through analyses of raw and commercial honey samples. The limit of detection was equal to 40 microg kg(-1). The precision and accuracy of the method were evaluated trueness honey samples spiked at three concentration levels (100-250-500 microg kg(-1)). The intra-laboratory coefficient of variation (from 9.2 to 10.6%) and mean recovery values (from 81.4 to 86.6%) were satisfactory. The calibration curve was linear in the range 0.125-2 microg ml(-1), with a determination coefficient R2 of 0.9999. Rotenone levels in honey samples from bees treated with this miticide were in the range 120-430 microg kg(-1).
