College of Chemical Engineering, Ningbo University of Technology, Ningbo, 315016, Zhejiang, China.
Ningbo Academy of Inspection and Quarantine, Ningbo, 315012, Zhejiang, China.
Anal Bioanal Chem. 2021 Mar;413(7):1871-1882. doi: 10.1007/s00216-021-03155-4. Epub 2021 Jan 19.
In this study, a novel method which involved in-tube solid-phase microextraction (SPME) using an attapulgite (ATP) nanoparticles-based hydrophobic monolithic column was successfully developed. It was coupled with high-performance liquid chromatography-ultraviolet detection for the determination of three phosphodiesterase-5 (PDE-5) inhibitors, including thiosildenafil, pseudovardenafil, and norneosildenafil, in functional foods. The monolithic column was prepared by one-step polymerization, using 3-trimethoxysilylpropyl methacrylate-modified ATP nanoparticles and 1-butyl-3-vinylimidazolium bromide (VBIMBr) as the functional monomers, and ethylene glycol dimethacrylate (EDMA) as the cross-linker. The obtained poly(ATP-VBIMBr-EDMA) monolith was characterized by scanning electron microscopy equipped with energy-dispersive analysis of X-ray, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction. The adsorption capacity, up to 2.00 μg/cm calculated by the Langmuir isotherm model, was about six times that of the poly(VBIMBr-EDMA) monolith. Crucial factors affecting the extraction efficiency, including sample solvent, elution solvent, flow rates of sampling loading and elution, sample loading volume, and elution volume, were investigated in details. Under the optimal in-tube SPME conditions, the proposed method showed good reproducibility with run-to-run, column-to-column, and batch-to-batch relative standard deviations less than 7.2%, and low limits of detection of 0.5-0.9 ng/mL in real samples. Thiosildenafil was detected in four types of functional foods with the contents of 1.30-4.78 μg/g. This newly proposed in-tube SPME method based on poly(ATP-VBIMBr-EDMA) monolith may provide a simple, efficient, and promising alternative to daily monitoring of PDE-5 inhibitors in functional foods.
在这项研究中，成功开发了一种涉及使用凹凸棒土（ATP）纳米粒子基疏水性整体柱的管内固相微萃取（SPME）的新方法。它与高效液相色谱-紫外检测相结合，用于测定三种磷酸二酯酶-5（PDE-5）抑制剂，包括硫代西地那非、伪伐地那非和诺雷司非，在功能性食品中。整体柱是通过一步聚合制备的，使用 3-三甲氧基硅丙基甲基丙烯酸酯改性的 ATP 纳米粒子和 1-丁基-3-乙烯基咪唑溴（VBIMBr）作为功能单体，以及乙二醇二甲基丙烯酸酯（EDMA）作为交联剂。所得的聚（ATP-VBIMBr-EDMA）整体柱通过扫描电子显微镜配备 X 射线能量色散分析、傅里叶变换红外光谱、热重分析和 X 射线衍射进行了表征。通过 Langmuir 等温模型计算，吸附容量高达 2.00μg/cm，约为聚（VBIMBr-EDMA）整体柱的六倍。详细研究了影响萃取效率的关键因素，包括样品溶剂、洗脱溶剂、采样加载和洗脱流速、样品加载量和洗脱量。在最佳管内 SPME 条件下，该方法具有良好的重现性，运行间、柱间和批间相对标准偏差小于 7.2%，在实际样品中的检出限低至 0.5-0.9ng/mL。在四种类型的功能性食品中检测到了硫代西地那非，含量为 1.30-4.78μg/g。这种基于聚（ATP-VBIMBr-EDMA）整体柱的新提出的管内 SPME 方法可能为日常监测功能性食品中的 PDE-5 抑制剂提供一种简单、高效、有前途的替代方法。
