Publish Time: 2022-03-01 Origin: Site
Veterinary drugs mainly include serum products, vaccines, diagnostic products, microecological products, Chinese herbal medicines, proprietary Chinese medicines, chemicals, antibiotics, biochemical drugs, radioactive drugs, topical pesticides, disinfectants, etc. So what are the commonly used methods for veterinary drug residue detection? Let's take a look.
Here is the table of contents:
l Instrument detection
l Microbial detection
l Immunological assay
First, high-performance liquid chromatography and its hyphenated technology. High-performance liquid chromatography mainly uses the distribution coefficients of different substances in different phases, uses the mobile phase to elute the substances that need to be monitored in the stationary phase, separates the components in the column, and uses the corresponding equipment for veterinary drugs detection. It has the advantages of good performance and separation efficiency and high sensitivity. Some experts used the combination of high-performance liquid chromatography and fluorescence detection technology to detect the residues of florfenicol in eggs, and the obtained correlation coefficient could reach more than 0.999, indicating that the method has a good linear relationship. Second, gas chromatography and its hyphenated technology. The basic principle of gas chromatography is to separate and analyze the components based on the difference in the distribution coefficient between the mobile phase and the stationary phase. It also has high separation efficiency and sensitivity, and the sample amount is relatively small, which can greatly improve the level of veterinary powder residue detection, and has even become the most typical detection method. Third, thin layer chromatography. The basic principle of thin-layer chromatography is to ensure that the mobile phase can realize the cycle of adsorption, desorption, re-adsorption, and re-desorption utilizing the difference in the adsorption capacity of different components to the adsorbent in the stationary phase, to realize the realization of each component. Thin-layer chromatography is a simple and fast chromatographic analysis method, which can realize the simultaneous determination of multiple veterinary drugs samples, and the analysis cost is low, but the reproducibility is relatively poor. Compared with the above two methods, the sensitivity and resolution are also slightly insufficient, so it is limited in practical application.
The microbial detection method is mainly microbial inhibition analysis. According to the inhibitory effect of veterinary drugs on specific microorganisms, qualitative analysis of drug residues in samples is carried out. In practical applications, the microbial detection method has the characteristics of simple sample processing and a high recovery rate and can be used for the analysis and screening of veterinary drug residues. In recent years, some researchers have used specific microorganisms as working bacteria to determine the residues of veterinary external medicine in animal products or related tissues by using the circular filter paper method or the cup and plate method. It should be noted that the sensitivity and accuracy of the microbiological method are relatively low, and the specificity is lacking. Therefore, it is only suitable for the determination of total antibiotic residues and is easily interfered with by other antibiotics. From the perspective of ensuring the validity of the test results, it is necessary to use immunoassay or be determined by instrumental analysis.
Immunological detection mainly uses the specific reaction of antigen and antibody to detect related substances and applies it to the detection of veterinary drugs, which has obvious advantages and can be used for rapid detection of a large number of samples. Using complex equipment can meet the requirements of on-site testing of veterinary drugs. From the perspective of practical application, there are four common immunological detection methods. First, enzyme-linked immunosorbent assay. The enzyme-linked immunosorbent assay mainly adsorbs a known antigen on the surface of a solid-phase carrier, so that the enzyme-labeled antibody or antigen can react on the solid-phase surface, and then quantitatively detects the antigen or antibody according to the color of the reaction. With the development and maturity of technology, enzyme-linked immunosorbent assay (ELISA) accounts for more than 90% of pesticide residue detection and has achieved remarkable results. Second, colloidal gold immunoassay. The colloidal gold immunoassay mainly combines the sample to be tested with the colloidal gold-labeled antibody immobilized on the test strip, and an immune reaction occurs. The reaction has the characteristics of high specificity and high affinity. If the sample is high, the sample will be enriched in the detection area, and then a color reaction will occur. According to the color development result, the testing personnel can conduct a qualitative analysis of the substance, which has a good application effect in the rapid primary screening of drug residues. Third, radioimmunoassay. The radioimmunoassay mainly uses the basic principle of radioactive receptor competition to rapidly detect veterinary external medicine residues in livestock and poultry products. The sample pretreatment of this method is relatively simple, and the total residues of sulfonamides can be preliminarily screened. Fourth, chemiluminescence immunoassay. Chemiluminescence immunoassay is an analytical method based on the relationship between chemiluminescence intensity and the content of the analyte. Its application in the detection of residues in veterinary tablets is similar to enzyme-linked immunosorbent assay, which can be detected directly or indirectly.
The above is about the commonly used methods in veterinary drugs residue detection. If you are interested in veterinary drugs, veterinary external medicine, veterinary oral solutions, you can contact us. Our website is https://www.topsurfholding.com/. I look forward to your arrival very much and hope to cooperate with you.