title: Spectrophotometric Determination of Cr(III) and Pb(II) Using Their Complexes with 5,11,17,23-Tetra[(2-ethyl acetoethoxyphenyl)(azo)phenyl]calix[4]arene.
abstract: New complexes of 5,11,17,23-tetra[(2-ethyl acetoethoxyphenyl)(azo)phenyl]calix[4]arene (TEAC) with Pb(II) and Cr(III) were prepared in basic solution with a mixture of MeOH and H2O as solvent. The ratio of TEAC and metal ion in complexes was found to be 1 : 1 under investigated condition. The complex formation constants (based on Benesi-Hildebrand method) for TEAC-Pb(II) and TEAC-Cr(III) were 4.03 × 10(4) and 1.2 × 10(4), respectively. Additionally, the molar extinction coefficients were 5 × 10(4) and 1.42 × 10(4) for TEAC-Pb(II) and TEAC-Cr(III), respectively. The H-Point Standard Addition Method (HPSAM) has been applied for simultaneous determination of complexes formation of Cr(III)/Pb(II) and TEAC with concentration from 2 : 1 to 1 : 20 (w/w). The proposed method was successfully utilized to invest lead and chromium contents in plating wastewater samples. The results for several analyzed samples were found to be in satisfied agreement with those acquired by using the inductively coupled plasma mass spectrometry (ICP-MS) technique.
authors.affiliation: Department of Chemical Engineering, Industrial University of Ho Chi Minh City, 12 Nguyen Van Bao Road, Ho Chi Minh City 70000, Vietnam.
authors.forename: Le
authors.initials: L
authors.lastname: Van Tan
authors.affiliation: Saigon Technology University, 180 Cao Lo, Ho Chi Minh City 70000, Vietnam.
authors.forename: Tran
authors.initials: T
authors.lastname: Quang Hieu
authors.affiliation: Department of Chemical Engineering, Industrial University of Ho Chi Minh City, 12 Nguyen Van Bao Road, Ho Chi Minh City 70000, Vietnam.
authors.forename: Nguyen
authors.initials: N
authors.lastname: Van Cuong