Chemical Engineering Communications, Vol.200, No.5, 638-654, 2013
THIOCYANATE-ASSISTED SOLID PHASE ENRICHMENT OF Cu(II) USING PYRIDINE DERIVATIVE WITH X-RAY CRYSTALLOGRAPHIC EVIDENCE
Equimolar mixture of pyridine-2,6-dimethanol (PDM), and thiocyanate ion immobilized on silica serves as an efficient sorbent for selective retention of Cu(II) from other associated metal ions at mu gg1 level. The maximum sorption capacity for Cu(II) was found as 2.44mmolg1 at pH 6.0. The sorbed Cu(II) was completely eluted with 3molL1 HNO3 and measured with a flame atomic absorption spectrometer (FAAS). The structure of the extracted Cu(II) complex was confirmed by single-crystal X-ray structure analysis and Fourier transform-infrared (FT-IR) spectroscopy. Thermogravimetric analysis (TGA) of the isolated Cu(II) complex was performed to determine its thermal stability at the extraction temperature. The three sigma detection limit (N=15) of the method is 0.6 mu gmL1 with a relative standard deviation (RSD) of 0.1% (N=15). Pre-concentration factor of the method is 133. Slight interference from Mn2+ ion was eliminated by prior oxidation with potassium periodate. The developed method was tested for trace level separation and estimation of Cu(II) in certified reference materials and environmental samples. [Supplementary materials are available for this article. Go to the publisher's online edition of Chemical Engineering Communications for the following free supplemental resources: two tables providing details of the bond lengths and bond angles of the Cu(II) complex.]
Keywords:Copper(II);Crystal structure;Flame atomic absorption spectroscopy;Pyridine 2;6-dimethanol;Thiocyanate