FIA双光束扫描导数光度法测定工业废水中微量锡

Determination of Micro Tin in Industrial Wastewater by Flow Injection Analysis Integrated with Dual-beam Spectrophotometry

提出一种新的快速、高灵敏的流动注射导数光谱检测技术,即利用双光束分光光度计中样品池和参比池同时扫描的时间差Δt,产生的一阶导数光谱ΔA/Δt≈dA/dt进行定量分析.基于溴代十六烷基三甲胺(CTAB)存在下,锡与苯芴酮在酸性介质中生成的有色络合物在510nm处有特征吸收,利用自行组装的一套FIA系统,一次进样同时产生两个正峰和一个负峰四个拐点的一阶导数光度值(ΔA1,ΔA2,ΔA3,ΔA4),均与被分析样品锡含量成正比.实验表明,在酒石酸存在下,所有共存离子均不影响锡的显色反应,具有可靠的选择性,分析的灵敏度是普通方法的1.8倍;另外,进一步采用(ΔA=ΔA1+ΔA2+ΔA3+ΔA4)加和技术后,灵敏度高达4.8倍.

A novel faster and higher sensitive flow injection derivative spectrophotometry detection technology is proposed,that is,by double beam spectrophotometer in the sample cuvettes and the reference,scan time delay( Δt) produces the first derivative spectra( ΔA / Δt≈dA / dt) for quantitative analysis. While cetyltrimethylammonium bromide ( CTAB ) co-existing,tin and 9- phenyl-2,3,7-trihydroxy-6-fluorine generates colored coordination compound at 510 nm,w hich has the characteristics of absorption under acidic condition. The sample w hich w as injected into a set of self-developed FIA system produced a first derivative spectrophotometry w ith tw o positive peaks,a negative peak and four inflexion points( ΔA1 ,ΔA2 ,ΔA3 ,ΔA4 ) at the same time,w hich w ere all proportional to the content of tin. Experimental results show ed that coexist ion did not affect the color reaction of tin in the presence of tartaric acid,the sensitivity is 1. 8 times higher than normal method and a good selectivity w as maintained in this method. Additionally,the sensitivity approached 4. 8 times by using the plus technology( ΔA = ΔA1 + ΔA2 + ΔA3 + ΔA4 ) .