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    离子交换微柱在线富集-电感耦合等离子体原子发射光谱法测定黄芪中稀土元素

    On-Line Preconcentration of Rare-Earth Elements in Astragalus Membranaceus with Ion-Exchange Micro-Column and Their Determination by Inductively Coupled Plasma Atomic Emission Spectrometry

    • 摘要: 以阳离子交换树脂微柱为柱填充材料,采用电感耦合等离子体原子发射光谱法(ICP-AES)进行检测,研究了三种阳离子树脂在动态条件下对16种稀土离子的交换性能.并确定了最佳交换及洗脱条件.结果表明:005×7 树脂的富集效果最好,在4 mL·min-1的进样速度下稀土元素均被定量富集,用4 mol·L-1 HCl溶液能迅速地将微柱上稀土离子完全洗脱.富集倍数可达32~42倍,稀土元素的检出限为0.09~2.49 μg·L-1,相对标准偏差为1.2%~4.7%(n=6).方法应用于茶叶标准样品中稀土元素的测定,其测定值与标准值吻合.并对内蒙古产区的黄芪中的稀土元素进行了测定,加标回收率在91%~110%之间.

       

      Abstract: An analytical circuit,including a FIA manifold for separation and preconcentration of rare-earth (RE) elements from the Chinese medicine astragalus membranaceus with ion-exchange micro-column and the detection unit of ICP-AES,was designed and proposed.The ion-exchange resin 005×7 was chosen for the separation,and filled in a micro-column,which was installed in the FIA flow system.As shown by the experimental results,16 RE elements were effectively separated from the sample matrix and enriched by passing the sample solution (pH 1.0) through the micro-column at a flow-rate of 4 mL·min-1,and the RE elements were eluted from the column quantitatively and rapidly with 4 mol·L-1 HCl,and an enrichment multiple of 32 to 42 was obtained.The eluate was used directly for ICP-AES determination.The proposed method has been applied to the determination of 16 RE elements in a sample of astragalus membranaceus from Inner Mongolia,and RSD′s (n=6) of the results obtained were in the range of 1.2%-4.7%.The detection limits (3S) found were in the range of 0.09-2.49 μg·L-1.Results of recovery test were found in the range of 91%-110%.In the analysis of a SRM of tea leaves (GBW 07605) for its RE contents by this method,the results obtained were in consistency with the certified values.

       

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