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超高效液相色谱串联质谱法同时快速测定牛奶中不同类型的11种兽药残留 总被引:1,自引:0,他引:1
建立了超高效液相色谱串联质谱测定牛奶中四环素类、青霉素类、磺胺类和泰乐菌素等11种兽药残留的检测方法。样品经乙腈超声提取后离心分离,上层清液稀释10倍后过0.2μm滤膜上机测定。在优化条件下,11种兽药在其线性范围内的相关系数均在0.998以上,定量下限(LOQ,S/N=10)为0.3~15μg/kg,在低、中、高3个水平下的加标回收率为81%~117%,相对标准偏差为0.6%~10.2%。方法用于实际牛奶样品中兽药残留量的测定,结果满意。 相似文献
995.
蔬菜中重金属含量测定方法的研究状况 总被引:1,自引:0,他引:1
综述了目前测定植株中重金属含量的4种主要方法,包括原子荧光光谱法(AFS)、原子吸收分光光度法(AAS)、电感耦合等离子体发射光谱法(ICP-AES)、电感耦合等离子体质谱法(ICP-MS)。分析了不同方法测定植株中重金属含量的原理、适用条件和研究现状,总结了其优缺点。得出电感耦合等离子体质谱法因其性能较强、实用性好的特点而在植株中的重金属含量测定方面具有明显的优势。同时展望了植株中重金属含量测定方法的发展前景。 相似文献
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997.
Lipid profiling of human plasma from peritoneal dialysis patients using an improved 2D (NP/RP) LC-QToF MS method 总被引:1,自引:0,他引:1
Min Li Baosheng Feng Yuan Liang Wei Zhang Yu Bai Wen Tang Tao Wang Huwei Liu 《Analytical and bioanalytical chemistry》2013,405(21):6629-6638
An improved online two-dimensional liquid chromatography-quadrupole time-of-flight mass spectrometry (2D LC-QToF MS) system was developed for the lipid profiling of human plasma, in which different lipid classes were separated by the first dimensional normal-phase (NP) LC and different lipid molecular species were separated by the second dimensional reversed-phase (RP) LC. This 2D LC-QToF MS system was built based on a ten-port, two-position valve as the interface, the conditions of which had been optimized and discussed in detail. As two loops were used to trap and transfer the first dimensional elute to the second dimension separately, this new interface suppressed the sample band broadening in the first dimensional column, increased the recovery and repeatability of 2D LC interface, and offered the possibility for the realization of not-stop-flow NP/RP 2D LC system. Finally, 190 endogenous lipid species out of 10 lipid classes were determined within a single run from the plasma of peritoneal patients. This method was also applied to identify the difference in lipid profile between plasma from peritoneal dialysis patients with bad volume status and peritoneal dialysis patients with good volume status. The discovery of 30 potential biomarkers would be helpful to the malnutrition, inflammation, and atherosclerosis syndrome investigation. 相似文献
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Xiaojia Huang Linli Chen Dongxing Yuan 《Analytical and bioanalytical chemistry》2013,405(21):6885-6889
A highly sensitive method was developed for the simultaneous determination of ten sulfonamides in pork and chicken samples by monolith-based stir bar sorptive extraction (SBSE) coupled to high-performance liquid chromatography tandem mass spectrometry. The samples were freeze-dried and extracted by acetonitrile, then enriched and further extracted by SBSE which was based on poly(vinylphthalimide-co-N,N-methylenebisacrylamide) monolith (SBSE-VPMB) as coating. To achieve optimum extraction performance of SBSE for sulfonamides, several parameters, including pH value and ionic strength in the sample matrix and extraction and desorption time, were investigated in detail. Under the optimal conditions, the limits of detection (S/N?=?3) for target sulfonamides were 1.2–6.1 ng/kg in pork and 2.0–14.6 ng/kg in chicken, respectively. Real samples spiked at the concentration of 0.5 and 5.0 μg/kg showed recoveries above 55 % and relative standard deviations below 12 %. At the same time, the extraction performances of target sulfonamides on SBSE-VPMB were compared with other SBSE based on porous monolith and commercial SBSE. Figure
? 相似文献
1000.
Xue Yan Xue‐Jiao Zhang Ya‐Xian Yuan San‐Yang Han Min‐Min Xu Ren'ao Gu Jian‐Lin Yao 《Journal of separation science》2013,36(21-22):3651-3657
A new approach was developed for the magnetic separation of copper(II) ions with easy operation and high efficiency. p‐Mercaptobenzoic acid served as the modified tag of Fe2O3@Au nanoparticles both for the chelation ligand and Raman reporter. Through the chelation between the copper(II) ions and carboxyl groups on the gold shell, the Fe2O3@Au nanoparticles aggregated to form networks that were enriched and separated from the solution by a magnet. A significant decrease in the concentration of copper(II) ions in the supernatant solution was observed. An extremely sensitive method based on surface‐enhanced Raman spectroscopy was employed to detect free copper(II) ions that remained after the magnetic separation, and thus to evaluate the separation efficiency. The results indicated the intensities of the surface‐enhanced Raman spectroscopy bands from p‐mercaptobenzoic acid were dependent on the concentration of copper(II) ions, and the concentration was decreased by several orders of magnitude after the magnetic separation. The present protocol effectively decreased the total amount of heavy metal ions in the solution. This approach opens a potential application in the magnetic separation and highly sensitive detection of heavy metal ions. 相似文献