mesoporous organosilicas with tyrosine framework as extractive phases for different pharmaceutical groups in biological samples prior to high performance liquid chromatography

Sample preparation techniques are usually required prior to the instrumental analysis because of low samples concentrations and their complexity [1]. mesoporous silica can be considered as promising materials in extraction due to their tunable pore size or shape, high surface area, thermal stability, and biocompatibility. moreover, their performance can be improved via functionalization with various organic groups [2]. in this research, tyrosine, a natural abundant amino acid, was incorporated within the channels of mesoporous materials through three ways of grafting, co-condensation, and periodic mesoporous organosilicon (pmo). the applicability of the fabricated structures in pipette tip-µ-solid phase extraction (pt-µ-spe) of different pharmaceutical groups such as anti- inflammatory, cardiovascular, antipsychotics, antiepileptics and antidepressants drugs were examined in conjunction with reversed phase liquid chromatography with uv detection. amino acid-bridged periodic exhibited the best performance due to homogeneously distribution of organic unit mesoporous in the framework without any blockage of mesoporous channels. in the following, pmo materials were synthesized by varying the concentration of the tyrosine- based precursor in the initial mixture. the prepared structures were confirmed by nmr, ft-ir, ms, small-angle xrd, n2 adsorption–desorption, tem, sem and edx analysis. under optimal conditions, the analytical performance of the developed method was also evaluated and precision, accuracy, and other figures of merit for selected analytes were achieved.