微波消解-火焰原子吸收光谱法测定刺梨中矿质元素含量

摘要

通过正交试验优化刺梨微波消解条件,并采用火焰原子吸收光谱法测定刺梨中Fe、Mg、Mn、Zn、Cu、Pb、Cd等7种元素的含量。结果表明,优化的刺梨消解程序为：采用HNO3-H2 SO4(4∶1)混合酸体系,固液比1∶20,微波功率600 W,消化温度140℃保持4 min。原子吸收光谱法测定7种元素的含量,方法检出限为0.003~0.080μg/mL,方法的加标回收率在96.25%~104.20%,相对标准偏差(RSD)小于3.04%,具有较好的准确度和精密度。测定结果显示,刺梨中Fe、Mg、Zn等含量丰富,Mn和Cu含量中等,而有毒金属元素Cd、Pb含量较低。%The microwave digestion conditions of Rosa roxburghii Tratt were optimized by orthogonal test, and then the contents of seven trace elements, including Fe, Mg, Mn, Zn, Cu, Pb and Cd in Rosa rox-burghii Tratt were determined by flame atomic absorption spectrometry ( FAAS ) . The results showed that the optimum conditions were as follows:the digestion agent was HNO3-H2SO4(4∶1),the solid-liquid ratio was 1∶20,the microwave power was 600 W,the digestion temperature was 140 ℃ and the hold time was 4 min. The detection limits were 0. 003—0. 080 μg/mL,and the recoveries of the FAAS method were between 96 . 25%—104 . 20%, the relative standard deviations ( RSD ) were lower than 3 . 04%. These figures showed that the FAAS method gave good accuracy and precision. The analytical results indicated that the contents of Fe,Mg,Zn were rich,the contents of Mn and Cu were medium,and the contents of Pb and Cd were low.