Study On The Properties Of Double Crosslinkers-Based Monolithic Materials In The Analysis Of Complex Samples

The compositions of complex samples are multifarious,which not only interferes with the results of the analysis,but also can easily contaminate the instrument and prolong the analysis time.It is more desirable for the analytical method to have better selectivity and higher sensitivity for the determination of complex samples.High-performance liquid chromatography?HPLC?is one of the most effective methods for analysing complex samples.However,for micro concentration of targets in complex samples,the stationary phase of HPLC is requested to have good ability to remove matrix interference.As a stationary phase for HPLC,the polymer monolith has good permeability and is easily modified to various chromatographic modes with good selectivity,which will promote rapid analysis of complex samples.In this work,two kinds of polymer monoliths were prepared using double crosslinkers,and the resulting monoliths were used as the solid-phase extraction?SPE?sorbent and stationary phase of HPLC,respectively,to pretreat biological samples and quantitatively detect the target components in complex food matrices.Firstly,an SPE monolithic sorbent was prepared via in-situ radical polymerization using1-vinyl-3-hexyl bromide imidazole as monomer,trimethylolpropane triacrylate and ethylene glycol dimethacrylate as binary crosslinker,and n-propanol and PEG200 as binary porogen.The monolithic material was characterized by scanning electron microscopy,mercury intrusion method and nitrogen adsorption-desorption method.The results show that the homemade monolithic material has a relatively uniform macro-,micro-and meso-porous structure with a specific surface area of 212.53 m² g^-1.The monolithic material was used as the SPE adsorbent and combined with a C18 column to establish a simultaneous online SPE-HPLC analysis method for five steroid hormones in human plasma.The results show that the prepared material has good ability for removing interference from the matrix in the plasma,the spiked recoveries of the method are in the range of 93.27%¹02.89%,and the limits of detection and limits of detection and limits of quantity of the five drugs are lower than 2 ng mL^-1 and 7 ng mL^-1,respectively.Secondly,a monolithic column was prepared via redox system initiation using dimethylaminoethyl methacrylate as monomer,trimethylolpropane triacrylate and triethylene glycol dimethacrylate as binary crosslinker,isopropanol and dodecanol as binary porogen.The homemade monolith with relatively uniform macro-porous structure was used as the stationary phase of HPLC to quantitatively analyse six flavor components including anethole,trans-cinnamaldehyde,hydroxy-?-sanotin,6-gingerol,8-gingerol and 10-gingerol in four spices,respectively.The results show that the spiked recoveries of the method are in the range of 92.02%¹18.59%,and the limits of detection and limits of quantity are lower than 0.043?g mL^-1 and 0.142?g mL^-1,respectively.The monolithic material based on ionic liquid exhibited good removing ability with a high specific surface area for the matrix such as protein in human plasma,which can effectively avoid the interference of sample matrix on quantitative determination of trace drugs,as well as protect the C18 column.Using monolithic column as the stationary phase of HPLC can shorten the analytical time and improve the efficiency.