Rapid Determination Of β-lactams Veterinary Drug Residues In Animal Tissue Using Radio-receptor Assay Method

Nowadays,β-lactams is one of antibiotics which is most used and most residue be tested from milk and tissue. Over the years, cup method is one of the most used screen test method of residue ofβ-lactams antibiotics. But cup method cann't tell the variety of antibiotics and has hign rate of false positive, because there are various bacteriostatic antibiotic and disturbing influence. Radio-receptor assay method is a new technology which tested by make radiolabelling at microbe. The mechanism of radio-recepter assay is combine of radioimmunoassay(RIA), enzyme-linked immunosorbent assay(ELISA), bioluminescence assay and chemiluminescence assay. This paper has designed the test programme of residue of p-lactams antibiotics, and has validated many parameter of test. The work is include below:1. Establish entire screen test programme of residue ofβ-lactams antibiotics by radio-recepter assay, and discuss the factors which can affect the result of test.2. Select and ensure paremeters of test include extract, pH value and time of incubation. Finally, choose MSU extracting buffer solution as extract, and 2 minute as time of incubation.3. Validate the selectivity and specificity of test method. Test the cross reaction use Penicillin G, Amoxicillin, Ampicillin, Cloxacillin, Dicloxacillin, Ceftiofur respectively, and the result shows that this method has good selectivity to theβ-lactams antibiotics. Validate the specificity of the test method used 1000μg/kg mixed standard solution prepared by Enrofloxacin, Neomycin, Gentamycin, Streptomycin, Spiramycin, Lincomycin, Tetracycline, Chloramphenicol, Sulfamethazine, erythromycin compounded with MSU buffer solution. All 6 test shows negative, and the test method has good specificity to theμ-lactams antibiotics.4. Study the detect limit of test method. The result of sensitivity test shows, the increase of drug cann't affect the cpm value be tested after drug concentration exceed 20μg/kg. The experiment of detect limit by various matrix shows, all ln(p) of matrix have good linear relationship with cpm value. The control point of pork, beef, chicken, fish, shrimp is 930, 865, 955, 994 and 890 respectively.5. Discuss the factors which affect the test, found that the value of microbe of samples and the fat of animal tissue may affect the result of test.6. Validate the test method in five independent laboratory respectively and all samples be added drug surpass detect limit shows positive. It prove that the test method has a good reproducibility.