Study On The Detection Methods Of Tetracycline Residues And N-nitrosamines In Dried Aquatic Products

In recent years,the safety of marine food has become increasingly prominent and has become the main bottleneck restricting the development of fisheries.In the process of aquatic product breeding,the unreasonable use of various drugs and additives,abuse and misuse,etc.,pose a threat to people's health and life safety.Establishing a simple,fast,safe and reliable pre-treatment method is very important for the detection of toxic and harmful substances in aquatic products.Therefore,this study uses multi-walled carbon nanotubes(MWCNTs)as the main adsorbent purification material,using QuEChERS pretreatment method and fast filtration purification method(m-PFC),combined with high performance liquid chromatography(HPLC)and gas chromatography-mass spectrometry Combined with(GC-MS)technology,3 kinds of tetracycline antibiotic residues and 9kinds of N-nitrosamines(NAMS)in dried aquatic products were detected and analyzed.The main research contents and results are as follows:1.A m-PFC purification device using MWCNTs composite material as adsorbent was established,and the QuEChERS method combined with HPLC was used to detect the residues of three tetracycline antibiotics in dried aquatic products.The sample was extracted with 0.1 mol/L Na₂EDTA-Mcllvaine and 0.1%formic acid acetonitrile,Na₂SO₄was added to promote the separation of the organic phase and the water phase,and placed at a low temperature of-20°C to promote the extraction of tetracycline antibiotics.C18,Mg SO₄and MWCNTs were used as adsorbents.Purify.The results showed that:tetracycline(TC),chlortetracycline(CTC)and oxytetracycline(OTC)three tetracycline antibiotics have good linearity in the corresponding concentration range,the correlation coefficient is greater than 0.9989,and the method quantification limit(LOQ)is 15?23 In the range of?g/kg,the overall recovery rate is good at three different concentration levels of 50,100,and 200?g/kg,and the relative standard deviation(RSD)is 1.6%to 10.6%,which can be used for the detection of actual samples.2.Based on the modified QuEChERS method combined with GC-MS,the detection of 9 NAMS in dried aquatic products was established.The QuEChERS method was improved,the extraction and adsorption conditions were optimized,and the best pretreatment method was obtained.Finally,acetonitrile was selected as the extraction solvent,PSA,Mg SO₄,C18 and MWCNTs were the adsorption purification materials,separated by DB-WAX column,and multiple reactions Detection in monitoring(MRM)mode.The results show that this method can meet the requirements of N-nitrosodimethylamine(NDMA),N-nitrosomethylamine(NMEA),N-nitrosodiethylamine(NDEA),N-nitrosodipropylamine(NDPA),N-nitrosodibutylamine(NDBA),N-nitrosopiperidine(NPIP),N-nitrosopyrrolidine(NPYR),N-nitrosomorpholine(NMOR),N-nitrosodiphenylamine(NDPHA)was tested with 9 NAMSs,and the results showed that 9 NAMS were well separated in 6.675 min?17.062 min,and the peak shape was more symmetrical,and the retention time and peak area were relatively good.Good reproducibility.The linearity is good in the range of 10?1000?g/L,the correlation coefficient is 0.9918?0.9999,the LOD and LOQ are 0.11?0.96?g/kg and 0.36?3.18?g/kg,respectively.The overall recovery rate of this method is good,and the RSD is in the range of 0.8%to 19.1%.In addition,the difference in the recovery rate between different matrices was compared,and it was found that there was no significant difference in the recovery rate in different matrices,which can be applied to the detection of NAMS in dried aquatic products.In addition,the main factors of NDMA exceeding the standard in dried aquatic products in the past three years are analyzed to provide a reference for the limit standard of NDMA in dried aquatic products.