Optimization Of LC-MS For Determination Of Tetracycline Residues In Livestock And Poultry Meat

Significance: China is a big country in the production and consumption of animal food.It has been at the forefront of the world since 2011.Since China joined WT0,the problem of veterinary drug residues has become increasingly serious affecting China's import and export and the country.The economic benefits,veterinary drug residues in animal-derived foods have gradually become a focus of attention in China and the world;monitoring and controlling veterinary drug residues in animal-derived foods,ensuring food safety,and establishing sensitive,accurate and reliable antibiotic residue detection The method has become the focus of research,and the study of tetracycline drug residues is one of the key aspects.China has established a standard test method for tetracyclines,but with the attention of the international community on food safety,the sensitivity of detection methods is also increasing.In recent years,liquid chromatography-mass spectrometry has made great progress,and it has been widely used in various fields,especially in the field of food analysis.Its separation ability,selectivity and sensitivity are extremely high.Not only can provide relative molecular mass,but also provide structural information.This test is based on GB/T 21317-2007,using liquid chromatography as a separation system,mass spectrometry as a method to optimize the test system.Objective: To establish a high-efficiency and feasible method for the simultaneous detection of tetracycline antibiotics LC-MS/MS in animal-derived foods based on GB/T 21317-2007,and optimize the extraction conditions,chromatographic conditions and mass spectrometry conditions to achieve efficient extraction.The operation is simple and the extraction result is accurate and credible.Methods: Searching for some analysis reports,related works,literature and research results of veterinary drug residues at the present stage,preliminary understanding of the research dynamics and frontier progress of veterinary drug residues at present stage;analyzing the influencing factors of target substance extraction,using comparative research method and empirical analysis Method,multi-level or multi-selection test on the same factor,the results obtained are averaged,and the coordinate map is produced to obtain the best advantage.Optimized conditions: The sample was extracted twice with 20 mL EDTA-Mcllvaine buffer and 5 mL methanol,sonicated for 20 min,centrifuged at 5?,10000 r/min for 15 min,filtered to obtain the supernatant,purified by HLB solid phase extraction column,passed 5 The impurities were eluted with a methanol aqueous solution,and then eluted with a methanol solution,reconstituted with 1 mL of methanol-0.1% formic acid water(20:80),and acetonitrile: 0.1% formic acid as a mobile phase,and detected by LC-MS/MS.Results: The four tetracycline antibiotics in this experiment had a good linear relationship.The peaks of the chromatographic peaks were sharp and there were no peaks,r were ?0.995.The detection limits of oxytetracycline,tetracycline,chlortetracycline and doxycycline were 0.1?g/kg;the recovery rate of target tetracycline spiked in livestock and poultry meat was 80%-110%;instrument reproducibility RSD<1%.Conclusion: Compared with GB/T 21317-2007,the optimized liquid quality testing method has higher selectivity and sensitivity,good recovery and reproducibility,and low requirements for analysis and practicality.More successful,with better promotion value.