A novel method was developed for extraction and enrichment of the four alkaloids (nuciferine, O-nornuciferine, armepavine and N-nornuciferine) from lotus leaf by coupling microwave-assisted extraction (MAE) with solid phase microextraction (SPME) before ultra-high-performance liquid chromatography (UHPLC) analysis. The influence parameters of MAE and SPME process including solvent-to-materials ratio, extraction solvent, irradiation power, extraction time were investigated. The method exhibited a good linearity within the range of 0.4–100 μg mL⁻¹ for nuciferine and O-nornuciferine, 0.1–25 μg mL⁻¹ for armepavine and N-nornuciferine (r² > 0.9990), respectively. Compared with the other extraction method, this method obviously shortens analytical time and enhances extraction efficiency. In addition, the concentration of the four alkaloids (nuciferine, O-nornuciferine, N-nornuciferine and armepavine) included two trace alkaloids were increased by 13, 10, 5 and 12 times after concentration, respectively. It was concluded that the newly MAE-SPME was an efficient method for the extraction and enrichment for alkaloids from herbs.

开发了一种新方法，通过微波辅助萃取（MAE）与固相微萃取（SPME）结合，从莲叶中提取和富集四种生物碱（核苷，邻-核苷，阿帕西汀和N-核苷），然后超高高效液相色谱（UHPLC）分析。研究了MAE和SPME工艺的影响参数，包括溶剂与物料的比，萃取溶剂，辐照功率，萃取时间。该方法显示出良好的线性度，其中核酸分子和O-核苷核酸在0.4–100μgmL ^-1的范围内，对于阿帕维宁和N-核酸核苷在0.1–25μgmL ^-1的范围内（r ² > 0.9990）。与其他提取方法相比，该方法明显缩短了分析时间，提高了提取效率。此外，包括两种痕量生物碱在内的四种生物碱（核苷，O-核苷，N-核苷和Armepavine）的浓度在浓缩后分别增加了13、10、5和12倍。结论是，新的MAE-SPME是从草药中提取和富集生物碱的有效方法。