Preparation And Application Of A Novel Molecularly Imprinted Monolithic Column Based On Metal Organic Frame Material

The separation and detection of the target substance with low content in the complex sample system is the most important step in the research of drug analysis,food analysis and environmental analysis.Therefore,it is of great significance to study the new materials and pretreatment methods applied in the separation analysis.Based on the technique of molecularly imprinted solid-phase extraction（MISPE）,the preparation and pretreatment effect of molecularly imprinted capillary monolithic column with metal-organic framework compound（MOF）and the application of high performance liquid chromatography（HPLC）to the analysis of target molecules in complex sample substrates were studied.The main research contents and results are as follows:1.The metal organic frame（UiO-66-NH₂）@molecularly imprinted capillary monolithic column（UiO-66-NH₂@MIPs capillary monolithic column）was prepared,which is used in combination with high-performance liquid phase（HPLC）for the applications to the enrichment,impurity removal and sensitive detection of Ponceau 4R in Carthami flos.UiO-66-NH₂@MIPs monolithic columns were prepared via in situ polymerization with HPLC for the detection of Ponceau 4R in Carthami flos sample.The adsorption and recognition properties of the UiO-66-NH₂@MIPs monolithic columns were investigated by HPLC,scanning electron microscopy（SEM）and infrared（IR）spectral analysis.The results indicated that UiO-66-NH₂@MIPs system has good linearity over the concentration range of 0.1-10.0 μg/mL with a correlation of coefficient>0.9999 and with a detection limit（S/N=3）of 2.7 × 10-4μg/mL.In addition,the mean recoveries of Ponceau 4R in Carthami flos ranged from 82.60%to 105.56%,and the RSD values were no more than 3.4%.The recycling experiments revealed that the the system could be reused for sensitive detection of Ponceau 4R in Carthami flos.It was determined that the column capacity of UiO-66-NH₂@MIPs was 0.178 μg/mg,which was obviously superior to that of other monolithic columns（0.089 μg/mg,0.080 μg/mg,and 0.111 μg/mg,respectively）.Under the selected conditions,not only the enrichment factor of UiO-66-NH₂@MIPs-HPLC was over 73-fold,meanwhile the system can reduce the interference of other impurity peaks.It indicates that a pretreatment method of enrichment and impurity removal with high sensitivity,low-cost and simple operation has been successfully developed to sensitively detect Ponceau 4R in Carthami flos.2.Computer simulation was used to filter the optimal functional monomer of the target molecule and we chose the appropriate dummy template molecule to replace template.The metal organic frame（UiO-67）@dummy template molecularly imprinted capillary monolithic column（UiO-67@MIPs capillary monolithic column）was prepared,which is used in combination with high-performance liquid phase（HPLC）for the applications to the enrichment,impurity removal and sensitive detection of of Aristolochic acid I in Aristolochia Manshuriensis Kom.The Gauss View software was used for modeling,and the Gaussian 09 software was used to optimize the geometric configuration of Aristolochic acid I and finctional monomer using DFT/B3LYP/6-31 g（d,p）basis group algorithm based on density functional theory.UiO-67@MIPs monolithic columns were prepared via in situ polymerization with HPLC for the detection of Aristolochic acid I in Aristolochia Manshuriensis Kom sample.The adsorption and recognition properties of the UiO-67@MIPs monolithic columns were investigated by HPLC and scanning electron microscopy（SEM）spectral analysis.The results are as follows.According to the analysis of computer simulation results,the optimal functional monomer is MAA.The results indicated that UiO-67@MIPs system has good linearity over the concentration range of 0.05-20.0 μg/mL with a correlation of coefficient>0.9994 and with a detection limit（S/N=3）of 0.65×10^-4 μg/mL.In addition,the mean recoveries of Aristolochic acid I in Aristolochia Manshuriensis Kom ranged from83.91%to 101.06%,and the RSD values were no larger than 3.4%.The recycling experiments revealed that the the system could be reused for sensitive detection of Aristolochic acid I in Aristolochia Manshuriensis Kom.It was determined that the column capacity of UiO-67@MIPs was 0.289 μg/mg,which was obviously superior to that of other monolithic columns（0.195 μg/mg,0.086 μg/mg and 0.064 μg/mg,respectively）.According to the comparison by HPLC,the enrichment factor of UiO-67@MIPs-HPLC was over 116-fold,meanwhile the system can reduce the interference of other impurity peaks.The above results confirmed that the research a pretreatment method of enrichment and impurity removal with high sensitivity,low-cost and simple operation has been successfully developed to sensitively detect Aristolochic acid I in Aristolochia Manshuriensis Kom.