火焰原子吸收光谱法测定纯铜和铜合金中铅  

Determination of lead in pure copper and copper alloy by flame atomic absorption spectrometry

作　　者：邹德霜[1] 李晓媛[1] 田伦富[1] 田东 代以春[1] ZOU De-shuang;LI Xiao-yuan;TIAN Lun-fu;TIAN dong;DAI Yi-chun(Institute of Machinery Manufacturing Technology,CAEP,Mianyang 621999,China)

机构地区：[1]中国工程物理研究院机械制造工艺研究所,四川绵阳621999

出　　处：《冶金分析》2018年第3期46-50,共5页Metallurgical Analysis

摘　　要：以往采用火焰原子吸收光谱法(FAAS)测定纯铜和铜合金中铅时,多采用分离富集法对铅进行富集或者采用标准加入法绘制校准曲线以消除基体的影响,操作较为繁琐。实验考察了不同含量铜基体对铅测定的影响,结果表明,当溶液中铜的质量浓度不大于20mg/mL时,铜对铅测定的影响基本可忽略,当溶液中铜的质量浓度为20~80mg/mL时,铜对铅测定的干扰不可忽略。因此实验提出,对于铅质量分数不小于0.05%的样品,采用铅标准溶液系列直接制作校准曲线,对于铅质量分数小于0.05%的样品,采用不含铅的高纯铜进行基体匹配绘制校准曲线的方法以消除基体干扰,最终实现了FAAS对纯铜和铜合金中质量分数大于0.002%的铅的测定。考察了酸介质和酸度对测定的影响,最终选择硝酸(1+1)溶解样品。根据不同样品量和不同的稀释因子,通过计算设计了3种系列标准溶液绘制校准曲线,使得校准曲线用标准溶液中酸的浓度与样品溶液中酸的浓度相同从而避免了酸度对测定的影响。将实验方法应用于纯铜、铜合金标准样品中质量分数在0.004%~2.7%之间铅的测定,测得结果与认定值基本一致,相对标准偏差(RSD,n=7~9)为0.7%~1.8%。During the determination of lead in pure copper and copper alloy by flame atomic absorption spectrometry(FAAS),the separation enrichment method was usually adopted for the enrichment of lead,or the standard addition method was used to prepare calibration curve to eliminate the matrix effect.As a result,the operation was relatively complicated.The effect of copper matrix with different content on the determination of lead was investigated.The results showed that the influence of copper on the determination of lead could be basically ignored when the mass concentration of copper in solution was not more than 20 mg/mL.However,the interference of copper with the determination of lead could not be ignored when the mass concentration of copper in solution was in range of 20-80 mg/mL.Therefore,the calibration curve was directly prepared with standard solution series of lead for the sample with lead mass fraction not less than 0.05%.When the mass fraction of lead in sample was less than 0.05%,the high-purity copper without lead was used for matrix matching to prepare calibration curve to eliminate the matrix interference.Consequently,a determination of lead with mass concentration higher than 0.002%in pure copper and copper alloy by FAAS was established.The effect of acid medium and acidity on determination was investigated.Nitric acid(1+1)was finally selected to dissolve sample.According to various sample amounts and dilution factors,three types of serial standard solution were designed to prepare calibration curve.The concentration of acid in standard solution for preparation of calibration curve was the same to that in sample solution,thus avoiding the influence of acidity on determination.The experimental method was applied for determination of lead in certified reference materials of pure copper and copper alloy with mass fraction in range of 0.004%-2.7%.The results were basically consistent with the certified values.The relative standard deviations(RSD,n=7-9)of determination results were between 0.7%and 1.8%.

关 键 词：纯铜 铜合金 铅 火焰原子吸收光谱法(FAAS) 

分 类 号：O657.31[理学—分析化学]