微波萃取-CE-ICP-OES分析铁皮石斛中钙镁形态

Analyzing speciation of calcium and magnesium in microwave extract of Dendrobium officinal using capillary electrophoresis and inductively coupled plasma optical emission spectrometry

利用微波萃取-毛细管电泳(CE)-电感耦合等离子体原子发射光谱(ICP-OES)联用技术,在电泳缓冲溶液为50 mmol/L NaAc-HAc(pH 5.5)、电泳电压为20 kV的条件下,分析中草药铁皮石斛中钙镁元素的形态。结果表明,铁皮石斛中钙以6种形态存在,镁以3种形态存在;以标准游离钙镁表征得到铁皮石斛中游离态钙镁的含量分别为5.95、5.27 mg/L;在最佳试验条件下,钙、镁检出限分别为0.031、0.025 mg/L,加标回收率为96.1%～98.3%。说明该方法用于分析铁皮石斛中钙镁形态是可行的,其为中药中金属元素形态研究提供了一条可靠途径,对中药开发利用及相关药物研究具有重要参考价值。

The present study is an attempt to analyze the speciation of calcium and magnesium in microwave extract of Dendrobium officinal by capillary electrophoresis （CE） and inductively coupled plasma optical emission spectrometry （ICP-OES）. NaAe-HAc （50 mmol. L-1, pH = 5.5） was used as electrophoretie buffer with 20 kV voltage. The results showed that there were six different speciations of calcium and three different speciations of magnesium in Dendrobium offlcinal extract. The contents of free calcium and magnesium in Dendrobium officinal extract were 5.95 and 5.27 mg/L spiked with 5 mg, L-1 free calcium and megnesium, respectively. Under the optimal conditions, the detection limit of calcium and mag- nesium were recorded as 0.031 and 0.025 rag. L-1 respectively, with the recovery rate ranging from 96.1-98.3%. It was found that this method can be effectively applied to analyze the speciation of calcium and magnesium in Dendrobium officinal. It provides a reliable approach to study the speeiation of metal elements in traditional Chinese medicine and an important reference for further studies.