Dai Xingping, Wang Dongsheng, Li Hui, Chen Yanyi, Gong Zhicheng, Xiang Haiyan, Shi Shuyun, Chen Xiaoqing
Department of Integrated Traditional Chinese and Western Medicine, Key Laboratory of Traditional Chinese Medicine Gan Organ of SATCM, Xiangya Hospital, Central South University, Changsha 410008, PR China.
School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China.
J Chromatogr A. 2017 Feb 10;1484:7-13. doi: 10.1016/j.chroma.2017.01.022. Epub 2017 Jan 9.
Polar and hydrophilic properties of hydroxybenzoic acids usually made them coelute with interferences in high performance liquid chromatography (HPLC) analysis. Then selective analysis of them was necessary. Herein, hollow porous ionic liquids composite polymers (PILs) based solid phase extraction (SPE) was firstly fabricated and coupled online with HPLC for selective analysis of hydroxybenzoic acids from complex matrices. Hollow porous PILs were firstly synthesized using Mobil Composition of Matter No. 48 (MCM-48) spheres as sacrificial support, 1-vinyl-3-methylimidazolium chloride (VMIMCl) as monomer, and ethylene glycol dimethacrylate (EGDMA) as cross-linker. Various parameters affecting synthesis, adsorption and desorption behaviors were investigated and optimized. Steady-state adsorption studies showed the resulting hollow porous PILs exhibited high adsorption capacity, fast adsorption kinetics, and excellent specific adsorption. Subsequently, the application of online SPE system was studied by selective analysis of protocatechuic acid (PCA), 4-hydroxybenzoic acid (4-HBA), and vanillic acid (VA) from Pollen Typha angustifolia. The obtained limit of detection (LOD) varied from 0.002 to 0.01μg/mL, the linear range (0.05-5.0μg/mL) was wide with correlation coefficient (R) from 0.9982 to 0.9994, and the average recoveries at three spiking levels ranged from 82.7 to 102.4%, with column-to-column relative standard deviation (RSD) below 8.1%. The proposed online method showed good accuracy, precision, specificity and convenience, which opened up a universal and efficient route for selective analysis of hydroxybenzoic acids from complex samples.
羟基苯甲酸的极性和亲水性质通常使其在高效液相色谱（HPLC）分析中与干扰物共洗脱。因此，对它们进行选择性分析是必要的。在此，首次制备了基于中空多孔离子液体复合聚合物（PILs）的固相萃取（SPE），并将其与HPLC在线联用，用于从复杂基质中选择性分析羟基苯甲酸。首先以莫来石48（MCM-48）球体为牺牲载体、1-乙烯基-3-甲基咪唑氯盐（VMIMCl）为单体、乙二醇二甲基丙烯酸酯（EGDMA）为交联剂合成了中空多孔PILs。研究并优化了影响合成、吸附和解吸行为的各种参数。稳态吸附研究表明，所得中空多孔PILs具有高吸附容量、快速吸附动力学和优异的特异性吸附。随后，通过对狭叶香蒲花粉中原儿茶酸（PCA）、4-羟基苯甲酸（4-HBA）和香草酸（VA）的选择性分析，研究了在线SPE系统的应用。获得的检测限（LOD）在0.002至0.01μg/mL之间，线性范围（0.05 - 5.0μg/mL）宽，相关系数（R）在0.9982至0.9994之间，三个加标水平的平均回收率在82.7%至102.4%之间，柱间相对标准偏差（RSD）低于8.1%。所提出的在线方法具有良好的准确性、精密度、特异性和便利性，为从复杂样品中选择性分析羟基苯甲酸开辟了一条通用且高效的途径。
