电镀钝化液类复杂样品中Cr^(6+)的检测技术研究

Detection Technology of Cr^(6+) in Complex Sample Such as the Electroplating Passivation Solution

在Cr6+的检测分析中,电镀钝化液是一种特殊复杂样品,其复杂性在于其中含量大量未知的金属离子在比色分析中会和二苯碳酰二肼络合显色,并且样品本身就是具有很深的颜色,并且含有大量络合离子,这些因素干扰了Cr6+的比色分析,对相关产品的RoHS认证很难进行。文章采用络合萃取-比色的方法,用5-Br-PADAP在样品前处理阶段进行络合,然后用萃取分离的方法去掉干扰的金属离子,然后进行比色分析。文中也讨论了萃取时pH的选择。通过萃取-比色法对5种不同厂家的电镀钝化液样品进行加标分析,显示其回收率一般在95%左右,效果良好。

The electroplating passivation solution is a special complex samples,during the detection and analysis of Cr^6 ＋,the content of which lies in the complexity of a large number of unknown metal ions that complexed with diphenyl hydrazine,and the samples are all deep color,the result of test of Cr^6 ＋ will be untrusted,so ROHS certification can’t be passed.In this paper,complexation extraction-colorimetric method is used for analysis of Cr^6＋.5-Br-PADAP solution is used in pre-treatment stage for complex,the interfering metal ions is removed after extraction,then the colorimetric analysis for Cr^6 ＋ is easily.The paper discussed the pH of complex solution also.Five different electroplating passivation samples be tested with standard addition,showed the recovery rate is generally 95 %.