Establishment Of Two Methods For Detection Of The Residues Of Benzimidazole And Pyrethroid

Benzimidazole and pyrethroid drugs are two groups of anti-parasitic drugs commonly used in veterinary practice.Their abuse in food-producing animals is definitely cause residues in animal derived food,posing a serious threat to the health of consumers.In this paper,a molecularly imprinted polymer capable of broad recognizing benzimidazoles or pyrethroids was first synthesized.A chemiluminescence detection method and a binary fluorescence detection method were established by using molecularly imprinted polymers as the identification element.This experiment used these two methods to detect the residues of these two drugs in beef and mutton.First of all,the three-dimensional conformations and structural parameters of benzimidazoles and pyrethrins were analyzed by computational simulation technique to screen out the group specific template drug molecules,separately.Molecularly imprinted polymers of benzimidazole were synthesized using mebendazole as a template.At the same time,2-aminobenzimidazole was conjugated with horseradish peroxidase to form an HRPlabeled hapten.A direct competitive chemiluminescence method was established by coating the recognition element molecularly imprinted polymer onto a 96-well plate,adding standard solutions for competitive absorption with HRP-labeled hapten,and inducing luminescence through Luminol-hydrogen peroxide system.The results showed that the method can detect 8 benzimidazoles simultaneously with the detection limits of 1.5-21 pg/mL and recoveries of 65.8%-91.2%in beef and mutton.Moreover,this method can be reused four times.Secondly,2-aminobenzimidazole and 4-aminodiphenyl ether were combined with fluorescein isothiocyanate and dansulfonyl-chloride pair respectively to form two fluorescent markers.The imprinted microspheres were coated in a 96-well plate,and the standard solution was added to combine with two kinds of fluorescent markers competitively.A binary direct competitive fluorescence method was established based on the different excitation/emission wavelengths of the two kinds of fluorescent markers.The results showed that the method was suitable to simultaneously detection of 8 benzimidazoles and 10 pyrethals with the detection limit of 4.2-17 ng/mL.The recoveries were 67.7%-109%in beef and mutton.And this method can be repeated five times.This paper established molecularly imprinted polymer as recognition elements chemiluminescence method and dual fluorescence method,with the advantages of simple operation,ultrahigh sensitivity,high selectivity,and cost effective.The method can be used for the determination of benzimidazole and pyrethroid residues,which is of great significance to the safety of animal food and the health of consumers.