三七中几种重金属含量测定

2011年度本科生毕业论文（设计）

原子荧光法测定三七中的砷和汞

院－系：理学院化学系

专业：化学

年级： 2007 级

学生姓名：朱首林

学号： 200702050235

导师及职称：潘青山（助教）

2011年5月

2011 Annual Graduation Thesis of the College Undergraduate

Atomic Fluorescence Spectrometric

Determination of Arsenic and Mercury

in Notoginseng

Department: College of Science

Major: Chemistry

Grade: 2011

Student’s Name: Zhu Shoulin

Student No.: 200702050235

Tutor: assistant Pan Qingshan

May, 2011

毕业论文（设计）原创性声明

本人所呈交的毕业论文（设计）是我在导师的指导下进行的研究工作及取得的研究成果。据我所知，除文中已经注明引用的内容外，本论文（设计）不包含其他个人已经发表或撰写过的研究成果。对本论文（设计）的研究做出重要贡献的个人和集体，均已在文中作了明确说明并表示谢意。

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摘要

本文用原子荧光光谱法测定三七中砷和汞的含量。研究了载流的盐酸浓度、硼氢化钾浓度及仪器工作条件等对测定影响的因素，建立了原子荧光光谱法测定三七中砷、汞的最佳工作条件。同时，用HNO3-H2O2体系高压消解三七试样，在确定的最佳工作条件下测定了三七中砷、汞的含量。实验结果表明，砷标准溶液浓度在0～10ug/L范围内，用5%盐酸载流液和2%浓度的硼氢化钾在290V负高压条件下测定所得荧光强度线性关系最好，回归方程为：A= 108.922C + 11.099 r=0.9999，测得三七样品中砷的平均含量为0.4288mg/kg，低于国家食品限量（以总砷计）≤0.7mg/kg[1]，方法的检出限为0.00571ug/L, RSD为0.39%，回收率试验所得结果为：90.2%～103.5%，平均回收率为96.3%；汞标准溶液浓度在0～2ug/L范围内，用5%盐酸载流液和2%浓度的硼氢化钾在270V负高压条件下测定所得荧光强度线性关系最好，回归方程为：A=1882.257C +108.357 r=0.9988，测得三七样品中汞的平均含量为0.0208mg/kg，稍高于国家食品限量（以总汞计）≤0.02mg/kg[2]，方法的检出限为0.000522ug/L，RSD为0.08%，回收率试验所得结果为82.8%～104.8%，平均回收率为90.7%。

关键词：原子荧光光谱法；三七；砷；汞

ABSTRACT

In this paper, useing atomic fluorescence spectrometric determination of content arsenic and mercury in notoginseng. Study of the current-carrying hydrochloric acid concentration, borohydride potassium concentration and working conditions of the instrument on the determination is affected, established atomic fluorescence spectrometric determination notoginseng of the arsenic and mercury in best working conditions. Meanwhile, HNO3 - H2O2 system with high resolution notoginseng specimens, In determining the best working conditions of the determination the content of arsenic and mercury in notoginseng. Experimental results show that the arsenic standard solution concentration in 0 ~ 10ug/L range, with 5% HCL

current-carrying fluid and 2% concentration of potassium in the borohydride negative pressure condition 290V determined from fluorescence intensity of linear relationship between the best, regression equation for: A = 108.922 C + 11.099 r = 0.9999,In the sample measured average of arsenic notoginseng content of 0.4288 mg/kg,lower than the national food limited (in total arsenic plan) more than 0.7 mg/kg[1] method to detect limit 0.00571ug/L,RSD was 0.39%, the recovery test results for: 90.2% ~ 103.5%, and the average recovery was 96.3%; Mercury standard solution concentration in 0 ~ 2ug/L range, with 5% HCL current-carrying fluid and 2% concentration of potassium in the borohydride 270V negative pressure condition determined from fluorescence intensity of linear relationship between the best, regression equation for: A = 1882.257C + 108.357 r = 0.9988. In the sample measured the average notoginseng for mercury content of 0.0208 mg/kg, lower than the national food limited (in total hg plan) more than 0.02 mg/kg[2] methods of detect limit for 0.000522ug/L, RSD was 0.08%, the recovery test results for 82.8% ~ 104.8%, and the average recovery was 90.7%.

Key word:Atomic Fluorescence Spectrometric; Notoginseng; Arsenic; Mercury