火焰原子吸收光谱法测定锡铅焊料中银

发布时间：2018-05-08 11:16

本文选题：火焰原子吸收光谱法(FAAS) + 锡铅焊料(焊锡)　；参考：《冶金分析》2016年12期

【摘要】：在采用火焰原子吸收光谱(FAAS)法对锡铅焊料(简称焊锡)中Ag进行测定时,Sn的存在会产生干扰。实验探讨了用FAAS测定时Sn对Ag的干扰,结果表明测定不大于2μg/mL的Ag时,Sn最大允许量为5mg/mL。据此,根据试样中Ag含量的高低,分别建立了分离Sn基体和不分离Sn基体后在1.8mol/L HCl介质中用FAAS测定焊锡中Ag的方法。利用Ag+可与过量Cl-反应生成[AgCl4]3-可溶络合物的特点,当试样中Ag质量分数大于0.02%时,采用HCl(3+1)-H_2O_2溶样或HCl-HBr-H_2O_2溶样及排Br后可直接用FAAS对试液进行测定;当Ag质量分数不大于0.02%时,采用HCl-HBr-H_2O_2体系溶样、排Br及挥发分离Sn基体后,再利用FAAS进行测定。实验表明,Ag质量浓度在0.2~2.5μg/mL范围内呈线性关系,相关系数为0.999 96,检出限为0.004μg/mL。干扰试验表明:在70~100℃低温下以HCl-H_2O_2排尽引入的Br和挥发分离Sn基体可防止Pb沉淀的溅跳;70%~90%Pb基体在HCl介质中可沉淀为PbCl2,此时,需静置至澄清后再测定以防止Pb沉淀对待测试液抽吸产生影响。将实验方法用于焊锡代表样及标样中0.002 3%~1.1%中Ag的测定,测定结果与其他方法(萃取光度法或电位滴定法)或认定值基本一致,相对标准偏差(RSD,n=9~11)为0.88%~4.8%。方法应用于实际样品分析,回收率为95%~106%。
[Abstract]:The existence of Sn will interfere with the presence of Sn in the determination of Ag in tin lead solder (FAAS) by flame atomic absorption spectrometry. The interference of Sn to Ag at FAAS determination is investigated. The result shows that the maximum allowable amount of Sn is 5mg/mL. when the Ag is not more than 2 u g/mL, and the separation S is established according to the Ag content in the sample. The n matrix and the Sn matrix are not separated from the matrix in the 1.8mol/L HCl medium by FAAS. The Ag+ can be used to react with the excess Cl- to produce the [AgCl4]3- soluble complex. When the Ag mass fraction of the sample is greater than 0.02%, the test solution is directly measured by HCl (3+1) dissolution sample or dissolution sample. When the mass fraction of Ag is not more than 0.02%, HCl-HBr-H_2O_2 system is used to dissolve samples, Br and volatilization Sn matrix, then FAAS is used for the determination. The experiment shows that the Ag mass concentration is linear in the range of 0.2~2.5 mu g/mL, the correlation coefficient is 0.99996, the detection limit is 0.004 u g/mL. interference test, which shows the HCl-H_2O_2 row at 70~100 C low temperature. The Br and volatilization Sn matrix can prevent the splash of Pb precipitation; 70%~90%Pb matrix can be precipitated in HCl medium and PbCl2. At this time, it is required to be static and then determined to prevent Pb precipitation from treating test liquid. The experimental method is applied to the determination of Ag in the representative sample of solder and the 0.002 3%~1.1% in the standard sample, and the results are determined with the others. The method (extraction photometric method or potentiometric titration) is basically the same, and the relative standard deviation (RSD, n=9~11) is applied to the actual sample analysis by the 0.88%~4.8%. method, and the recovery rate is 95%~106%.

【作者单位】：云南锡业集团公司研究设计院;
【基金】：国家质量监督检验检疫总局国家标准修订项目(2001-19A)
【分类号】：TG42;O657.31

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