Preparation,evaluation And Application In The Detection Of Basic Drugs Of Silica-Nanoparticles-Containing Hybrid Monolithic Column For Liquid Chromatography

A silica nanoparticle hybrid monolithic column was prepared for liquid chromatography by in-situ polymerization of commercialized pre-alkenylated silica nanoparticles of 10-20 nm in diameter and 3-sulfopropyl methacrylate potassium salt(SPMA)in the presence of ternary porogen consisting of cyclohexanol,methanol and water in a 150 ?m i.d.fused silica capillary.Under the condition of controlling the change of single preparation conditions such as porogen composition,total monomer concentration,organic functional monomer concentration,polymerization temperature and reaction time,a series of SHM columns(silica-nanoparticles-containing hybrid monolithic column)were prepared.Based on the SEM images and pressure-vs-flowrate curves corresponding to each SHM column the preparation conditions were selected,composition of polymerization mixtures were as follow: inorganic silica nanoparticles(10.0 mg),SPMA(3.0 mg),cyclohexanol(14.8 ?L),methanol(14.8 ?L),water(7.4 ?L)and 2,2-Azobisisobutyronitrile(0.125 mg);polymerization time,6 h;polymerization temperature,60?.Then,the physical properties of the SHM column were comprehensively evaluated,such as the microstructure,mechanical stability,permeability,swelling-shrinking behavior,binding capacity,column efficiency and preparation reproducibility.Compared with the general strong cation exchange monolithic column,the SHM column has the beneficial characteristics of the simple preparation process,mild conditions and easy to control,uniform pore structure,good mechanical stability,and large exchange capacity,good resistance to swelling-shrinking and good reproducibility.Finally,the SHM column was used to separate and measure the basic drugs Metformin(MET)and Ephedrine(EPH)in actual samples.After optimizing the chromatographic separation conditions,the contents of MET and EPH in the actual spiked samples were determined according to the continuous standard addition method.The obtained results shows that the recovery rate of the plasma samples spiked with MET is 99.4%,the intra-day precision is 6.0%(RSD%,n = 3),the recovery rate of the spiked urine samples is 102.4%,the intra-day precision is 3.7%(RSD%,n = 3);the recovery rate of the plasma sample spiked with EPH is 98.0%,the intra-day precision is 4.1%(RSD%,n = 3),the recovery rate of the spiked urine sample is 101.0%,the intra-day precision is 4.3%(RSD%,n = 3).The experimental results indicate that the SHM column is used for separation and determination of basic drugs with high recovery rate,high precision and fast separation speed,which provides a new method for monitoring the plasma drug concentration of basic drugs after clinical use.