干灰化原子吸收光谱法测定鱼腥草中微量元素和重金属含量

Content Determination of Microelements and Heavy Metal in Houttuynia cordata by Dry Ashing Atomic Absorption Spectrometry

[目的]为开发鱼腥草的食用价值和药用价值提供理论依据。[方法]利用干灰化法-火焰原子吸收光谱法测定鱼腥草中Fe、Cu、Mn和Pb的含量。[结果]各元素的标准曲线回归方程和相关系数如下：Pb：y=31.0163x＋0.0093,r=0.9998 Mn：y=4.4099x-0.0899,r=0.9970 Cu：y=5.02925x-0.05120,r=0.9989 Fe：y=8.1106x-0.1004,r=0.9971。鱼腥草中微量元素的含量比较高,在测定的3种微量元素中Fe的含量最高,有害元素Pb的含量较低。鱼腥草中Fe、Cu、Mn和Pb的含量均低于我国食品卫生标准及《药用植物及制剂进出口绿色行业标准》限量指标：重金属含量总量应≤20.0 mg/kg,Pb≤5.0 mg/kg。利用该法测定Pb、Cu、Mn和Fe的相对标准偏差分别为1.0%~3.0%、0.3%~0.4%、0.3%~0.4%和0.3%~0.4%。[结论]火焰原子吸收光谱法测定鱼腥草中的微量元素和重金属含量具有较高的灵敏度和准确度。

[ Objective ] The purpose was to supply theoretical basis for exploiting the edible and medicinal value of Houttuynia cordata. [ Method ] The contents of Fe, Cu, Mn and Pb in H. cordata were determined by dry ashing - flame atomic absorption spectrometry. [ Result ] The standard curve regression equations and correlation coefficients of all the determined elements were as follows： Pb：y = 31. 016 3x ＋ 0.0093, r=0.9998; Mn：y=4.4099x-0.0899, r=0.997 0; Cu. y=5.029 25x-0.051 20, r=0.998 9; Fe： y=8. 1106x- 0. 100 4, r =0.997 1. The contents of microelements was relatively high in H. cordata, among the 3 determined microelements, the content of Fe was highest and the content of harmful element Pb was relatively low. The contents of Fe, Cu, Mn and Pb in H. cordata were lower than the limited amout indices of Chinese food hygienic standard and green improt and export standard of medicinal plant preparation, which were that the total content of heavy metals was no more than 20.0 mg/kg and the content of Pb was no more than 5.0 mg/kg. The RSDs of determining Pb, Cu, Mn and Fe by this method were 1.0% - 3.0%, 0.3% - 0.4%, 0.3% - 0.4% and 0. 3% - 0. 4% resp. [ Conclusion ] The content determination of mieroelements and heavy metal in H. cordata by flame atomic absorption spectrometry had higher sensitivity and accuracy.