TXRF法测定淡竹叶中微量元素

Determination of trace elements in lophatherum gracile brongn by TXRF

目的:为了探讨淡竹叶中多种微量元素的同时、快速测定方法。方法:淡竹叶样品经过微波消解处理后,用全反射X射线荧光(TXRF)分析单一内标法同时测定其中的K、Ca、Fe、Co、Ni、Mn、Cu和Zn等微量元素。结果:确立了微波消解法作为前处理方法的最佳条件:100℃保持3 min,以5℃/min的速率升温至180℃,然后保持50 min。用微波消解-TXRF法测定了花粉标准物质中9种微量元素,并计算得到了TXRF测定淡竹叶中这8种元素的仪器检出限(LLD)范围为:0.002 mg/L(Co、Ni、Cu、Zn)～0.054 mg/L(K),方法检出限(LDM)范围为:0.004 mg/kg(Co、Ni、Cu、Zn)～0.122 mg/kg(K)。微波消解-TXRF测定各元素的相对标准偏差(RSD)在1.5%(Mn)～4.4%(Co)之间。结论:该方法操作简单、样品需用量少、检出限低,可适用于淡竹叶中多种元素的快速、同时测定。

Objective：To study the method using microwave digestion and TXRF for the determination of trace elements in lophatherum gracile brongn.Methods： The lophatherum gracile brongn was digested by microwave.And the internal standard method was used for TXRF measurement of trace elements（K,Ca,Ti,Mn,Fe,Ni,Cu and Zn）.Results： The optimum conditions of microwave digestion were starting from 100℃（for 3 min） to 180℃（for 50 min）,at the heating rate of 5℃/min.Eight elements,such as K,in GBW10026 were determined by TXRF with microwave digestion.And the lower limit of detection（LLD） and the limit of determination（LDM） of different elements in pollen were calculated.The LLD range of the nine elements was 0.002 mg/L（Co,Ni,Cu,Zn）~0.054 mg/L（K）and the LDM range of them was 0.004 mg/kg（Co,Ni,Cu,Zn）~0.122 mg/kg（K）.Under optimized conditions,the relative standard deviations（RSDs） were lower than 4.4%.Conlusion： The developed method has been applied to simultaneously determine the trace elements in lophatherum gracile brongn,with the advantages of simple operation,less consumption of sample and low detection limit.