Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials & Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Wuhan 430062, China.
J Chromatogr A. 2013 Aug 23;1304:10-7. doi: 10.1016/j.chroma.2013.06.060. Epub 2013 Jul 1.
The present work aims to synthesize an organic-inorganic hybrid caffeine imprinted monolith using one-step method. The synthesis conditions such as the type of inorganic precursor and porogenic solvent, the molar ratios of the monomer and cross-linker, the volume ratio of the inorganic alcoholysate and organic part were optimized. The morphology of the monolith was studied by scanning electron microscopy and Fourier transform infrared spectra. The imprinted factor of the monolith for caffeine reached 3.02. A simple, rapid and sensitive method for the determination of caffeine in children's milk using the organic-inorganic hybrid caffeine imprinted polymer monolith microextraction combined with high-performance liquid chromatography-photodiodes array detector was developed. Several parameters affecting the sample pretreatment were investigated, including the type, flow rate and volume of eluent, the flow rate and volume of sample solution. The assay exhibited a linear dynamic range of 8-500μgL(-1) with the correlation coefficient above 0.9987. Lower limits of detection (LOD, at S/N=3) and quantification (LOQ, at S/N=10) in children's milk samples were 2.7 and 8μgL(-1). Recoveries of caffeine from spiked children's milk ranged from 85 to 104% with relative standard deviations of less than 8.9%.
本工作旨在采用一步法合成有机-无机杂化咖啡因印迹整体柱。优化了合成条件，如无机前体和致孔溶剂的类型、单体和交联剂的摩尔比、无机醇解物与有机部分的体积比。通过扫描电子显微镜和傅里叶变换红外光谱研究了整体柱的形态。印迹因子达到 3.02。采用有机-无机杂化咖啡因印迹聚合物整体柱微萃取结合高效液相色谱-光电二极管阵列检测器，建立了一种简单、快速、灵敏的测定儿童牛奶中咖啡因的方法。考察了样品预处理的几个参数，包括洗脱液的类型、流速和体积、样品溶液的流速和体积。该测定方法在儿童牛奶样品中的线性动态范围为 8-500μg/L，相关系数均大于 0.9987。儿童牛奶样品中的检出限（LOD，S/N=3）和定量限（LOQ，S/N=10）分别为 2.7 和 8μg/L。咖啡因在儿童牛奶中的回收率在 85%至 104%之间，相对标准偏差小于 8.9%。
