Determination of residues of pyrethroid and organophosphorous ectoparasiticides in foods of animal origin.

Analytical methods were introduced for the determination of residues of ectoparasiticides containing pyrethroid and organophosphate active ingredients in foods. Milk and edible tissues of cows treated with three experimental ectoparasiticides (containing cypermethrin + diazinon, deltamethrin + diazinon and alphamethrin + diazinon, respectively) were assayed for the presence of active ingredient residues. Synthetic pyrethroid residues were not detected in any of the samples processed. Diazinon residues could only be detected in milk samples taken on the first day after treatment (0.005-0.025 mg/kg) and in liver and fat tissue samples taken on the day of slaughtering (0.12 and 0.01 mg/kg, respectively). Permethrin and propetamphos residues were determined in the skin, meat and liver of chickens kept on 'Blotic-B' treated litter and in eggs collected at different times after the treatment of layer houses. Permethrin residues could not be detected in any of the samples (< 0.01 mg/kg). Meat and fat tissues of chickens slaughtered on the day after treatment contained small amounts of propetamphos (0.003 and 0.02 mg/kg, respectively). In the case of chickens kept on the treated litter and slaughtered after one week, active ingredient was not detected in meat, but 0.006 mg/kg propetamphos was present in the fat. The residue content of other samples (liver, egg) was below the detection limit of the applied method at all sampling times. From the food toxicological point of view these pesticide combinations can be used safely if the recommended withdrawal period is observed between ectoparasiticide administration and slaughter.

Determination of acrinathrin residues in honey and beeswax.

The Asian bee mite (Varroa jacobsoni Oud.) causes variable damage in Hungarian apiaries due to the different and changing conditions. Plastic and wooden strips impregnated with synthetic pyrethroid-type active ingredients show a high efficacy against the mites. These treatments, however, may leave residues in bee products (honey, propolis, wax). After experimental treatment with Gabon PA 92, the levels of active ingredient (acrinathrin) residues were determined in honey and beeswax samples. The analytical results proved that the average concentration of acrinathrin residues was less than 0.01 mg/kg in honey and less than 0.10 mg/kg in beeswax. From the food-hygienic point of view it is favourable that the honey did not become 'contaminated' with acrinathrin during the experimental treatment. The analytical results serve as a basis for the registration of this veterinary product in Hungary.