高灵敏显色光度法测定电镀废水中的微量Zn(Ⅱ)  

Determination of Micro Zinc( Ⅱ ) in Electroplating Wastewater by Highly Sensitive Coloring Spectrophotometry

作　　者：罗道成[1,2] 卢艳萍[1] 汪威[1] 

机构地区：[1]湖南科技大学化学化工学院,湖南湘潭411201 [2]湖南科技大学煤炭资源清洁利用与矿山环境保护湖南省重点实验室,湖南湘潭411201

出　　处：《材料保护》2013年第9期64-65,8,共2页Materials Protection

摘　　要：HCl介质中存在硫氰化钾（KSCN）和聚乙二醇（PEG）时，罗丹明B（RhB）会与zn（Ⅱ）发生灵敏的显色反应，据此建立了一种测定电镀废水中微量zn（Ⅱ）的新光度法。结果表明：Zn（Ⅱ）与KSCN，RhB反应，生成了一种稳定的三元配位物Zn（SCN）4（RhB）2，其摩尔比为1：4：2；最大吸收波长为600nm，表观摩尔吸光系数为1．65×10^6（mol·cm），Zn（Ⅱ）含量在0～0．060mg／L内符合比耳定律；测得的电镀废水中的微量Zn（Ⅱ），与5-Br—DMPAP光度法相符，6次测定值的RSD〈4％；加标回收率为96．5％～102．0％。Based on the fact that sensitive coloring reaction takes place between Rhodamine B( RhB) and zinc( II) in HCl solution containing potassium rhodanate( KSCN) and polyethylene glycol( PEG),a highly sensitive coloring spectrophotometric method was established to determine micro zinc( II) in electroplating wastewater. Results showed that Zn( II) reacted with KSCN and RhB to form a stable ternary complex Zn( SCN) 4( RhB) 2 with a molar ratio of 1 ∶ 4 ∶ 2 as well as a maximum absorption wavelength of 600 nm and an apparent molar absorption coefficient of 1. 65 × 106L /( mol · cm),while Beer 's law was obeyed in zinc(Ⅱ) concentration range of 0 ~ 0. 060 mg / L. Moreover,the content of micro zinc( Ⅱ) in electroplating wastewater determined by the present method agreed well with that determined by 5-Br DMPAP spetrophotometric method; namely,the relative standard deviation of six cycle measurements was below 4%,and the labeled recoveries of samples were in the range of 96. 5% ~ 102. 0%.

关 键 词：电镀废水测定 分光光度法 罗丹明B 聚乙二醇 Zn(Ⅱ) 

分 类 号：O657.32[理学—分析化学]