毛细管电泳-激光诱导荧光法测定人参中铜和镉离子含量

Content Determination of Cd^(2+) and Cu^(2+) in Ginseng Radix et Rhizoma by Capillary Electrophoresis Coupled with Laser-induced Fluorescence

目的:建立高效毛细管电泳-激光诱导荧光法(high performance capillary electrophoresis-laser induced fluorescence,HPCE-LIF)测定Cu^(2+)和Cd^(2+)含量的方法,并将其应用于中药材人参重金属的检测。方法:Cu^(2+)与Cd^(2+)通过与荧光络合剂异硫氰酸荧光素酯-偶氮乙二胺四乙酸(fluorescein isothiocyanate isomer I-Aminobenzyl ethylene diamine tetraacetic acid,FITCABEDTA)柱前络合后,以熔融石英毛细管柱(75μm×60.2 cm,有效长度50 cm)为分离通道,经1 mol·L^(-1)NaOH溶液调pH至9.3的0.1 mol·L^(-1)硼酸溶液-0.1 mol·L-1SDS溶液(38.5∶61.5)作为缓冲溶液,分离电压25 kV,检测波长520 nm,毛细管温度25℃,自动压力进样5 s。结果:人参样品中Cu^(2+),Cd^(2+)分离效果良好,并且对两者进行了标准曲线、精密度、重复性和加样回收率试验,在1~150,2~200μg·L^(-1)线性关系良好(r>0.999 2),两者精密度RSD均<2.0%,表明精密度良好;两者重复性RSD均<3.7%,表明重复性良好;两者加样回收率分别为103.30%,100.33%,RSD 2.5%,2.8%。结论:采用毛细管电泳-激光诱导荧光法测定中药材人参中特定重金属,方法可行,很好地解决了中药材重金属离子含量低且不易分离的问题,为中药材重金属离子的检测提供一种新的方便快捷准确的方法,并且相信经过不断探索和改进研究,HPCE-LIF法可用于中药材中更多重金属离子的同时检测。

Objective： To establish a high performance capillary electrophoresis with laser-induced fluorescence （HPCE-LIF） detection method for simultaneous determination of cadmium and copper contents, and apply this proposed HPCE-LIF method for the detection of heavy metal in Ginseng Radix et Rhizoma. Method： After the complexation of Cu2＋ and Cd2＋ with fluorescein isothiocyanate isomer I-Aminobenzyl ethylene diamine tetraacetic acid （FITC-ABEDTA）, with a fused silica capillary （75 μm × 60.2 cm, effective length of 50 cm） as the separation channel, the carrier buffer was composed of 0. 1 mol＇L-1 boric acid-0. 1 mol·L-1 SDS （38.5：61.5 ） with pH adjusted to 9.3. The applied voltage was 25 kV and the capillary temperature was 25 ℃. The detection wavelength was at 520 nm, and the samples were injected into the capillary at a pressure for 5 s. Result： Cd2 ＋ andCu2＋ ions were well separated, and good linearity was found in the range of 1-150, 2-200 μg·L-1 for Cu2＋ and Cd2＋ ions. The RSD of precision was both less than 2.0% ; RSD of repeatability was both less than 3.7% , and the average recovery was 100.33% for Cd2＋ with RSD of 2.8% and 103.30% for Cu2＋ with RSD of 2.5%. Conclusion： Capillary electrophoresis-laser induced fluorescence could be used to detect certain heavy metals in Chinese traditional medicine Ginseng Radix et Rhizoma, and this method could make up for the shortcomings of low content of heavy metal ions and the difficulty in separation of traditional Chinese medicinal materials, and provide a new, convenient, fast and accurate method for detecting heavy metal ions of Chinese medicinal materials. It is believed that after continuous exploration and improvement research, HPCE-LIF can be used to detect more heavy metal ions in traditional Chinese medicine simultaneously.