Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, Greece.
International Forensic Research Institute, Department of Chemistry and Biochemistry, Florida International University, Miami, FL, USA.
J Sep Sci. 2019 Apr;42(7):1440-1450. doi: 10.1002/jssc.201801283. Epub 2019 Feb 11.
Capsule phase microextraction is introduced herein for the first time to determine four sulfonamide residues in milk samples (sulfanilamide, sulfadiazine, sulfamethizole, and sulfathiazole). The technique eloquently integrates filtration and stirring mechanism into the extraction device, as such no filtration of the sample is needed prior to introducing the extraction device into the sample, and when placed on a magnetic stirrer, the device spins itself in order to diffuse the sample, resulting in faster extraction equilibrium. Microextraction capsules consist of three main parts; a magnet, a cellulose fiber substrate coated with high performance sol-gel hybrid organic-inorganic sorbent, and a porous membrane. Various encapsulated sol-gel sorbents were tested in standard solutions prepared in deionized water and milk samples under different operational conditions. Analyte extraction time and elution time, type of sol-gel sorbent, elution solvent, as well as the ratio of the sorbent to the elution solvent were among the optimized conditions. The protocols that yielded the best absolute recovery rates were subsequently tested in various milk samples. Method validation was performed in terms of linearity, accuracy and precision, reusability and ruggedness using the Youden test. The examined sulfonamides were subsequently analysed by reversed phase high performance liquid chromatography with diode array detection.
胶囊相微萃取技术首次被用于测定牛奶样品中的四种磺胺类残留（磺胺、磺胺嘧啶、磺胺甲噁唑和磺胺噻唑）。该技术巧妙地将过滤和搅拌机制集成到萃取装置中，因此在将萃取装置引入样品之前不需要对样品进行过滤，并且当放置在磁力搅拌器上时，装置会自行旋转以扩散样品，从而更快达到萃取平衡。微萃取胶囊由三个主要部分组成；磁铁、涂有高性能溶胶-凝胶杂化有机-无机吸附剂的纤维素纤维基质，以及多孔膜。在不同操作条件下，在去离子水和牛奶样品中制备的标准溶液中测试了各种封装的溶胶-凝胶吸附剂。优化了分析物萃取时间和洗脱时间、溶胶-凝胶吸附剂的类型、洗脱溶剂以及吸附剂与洗脱溶剂的比例等条件。随后，在各种牛奶样品中测试了产生最佳绝对回收率的方案。使用约登测试对线性度、准确度和精密度、可重复性和稳健性进行了方法验证。随后使用反相高效液相色谱法结合二极管阵列检测对所检查的磺胺类药物进行了分析。
