Dual-wavelength spectrophotometric determinations of copper and its composition of the complex with eriochrome blue black R

✍ Scribed by Hong-Wen Gao

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 276 KB
• Volume: 114
• Category: Article
• ISSN: 0165-0513
• DOI: 10.1002/recl.19951140204

✦ Synopsis

Abstract

Copper has been determined by a modified dual‐wavelength spectrophotometric (DWS) method, using the reaction of Cu^II^ with eriochrome blue black R (EBBR) at pH 12, which is sensitive and selective in the presence of both pentadecyltrimethylammonium bromide (PTMAB) and ascorbic acid. The modified DWS can completely eliminate the effect of excess EBBR in its Cu^II^ solution and give the real absorbance of the produced chelate of Cu^II^ with EBBR, with increased analytical sensitivity and decreased error. The composition of the complex of Cu^II^ with EBBR can be determined easily and accuratively. Beer's law is obeyed over the concentration range of 0‐1.60 mg Cu per 1 and the true molar absorbance of chelate Cu(EBBR)~2~ at 550 nm has been computed as 1.80 · 10^4^ · mol^−1^ · cm^−1^. The detection limit of Cu is 0.04 mg. This method has been applied for the determination of trace amounts of copper in waste water with satisfactory results.