Abstract

A FACILE SYNTHESIS, CHARACTERIZATION AND COMPARATIVE STUDY OF CMHBH & CMTSC WITH LEAD (II) IN PRESENCE OF MICELLAR MEDIUM BY SPECTROPHOTOMETRY

Dr.D.Gopala Krishna* and Ch.Kethani Devi

ABSTRACT

Two simple, sensitive, rapid and selective Spectrophotometric methods have been developed for the determination of Pb (II) using newly synthesized reagents Cinnamaldehyde 4-hydroxy benzoylhydrazone (CMHBH) and Cinnamaldehyde thiosemicarbazone (CMTSC). Pb (II) forms an yellow coluored water-soluble complex with CMHBH and CMTSC at pH 9.0 and shows maximum absorbance at max 430, 410 nm in presence of micellar media respectively. At these wavelengths (max), the complex shows maximum absorbance while the reagent blanks shows negligible absorbance. Beer's law was obeyed in the range 0.158-5.18 μg/ml and the optimum concentration range from ringbom plot was 1.036-4.662 g/ml for CMHBH and CMTSC. The molar absorptivity and Sandell's sensitivity for the coloured solution were found to be 3.47x104 L mol-1 cm-1 and 0.0059-μg. cm-2 for Pb (II)-CMHBH, 3.02x104 L mol-1 cm-1, and 0.0068-μg. cm-2 for Pb (II)-CMTSC respectively. The interference effects of various diverse ions have been studied. Pb (II) forms 1:1 complex with CMHBH and CMTSC stoichiometry with stability constant 10.95x106 for Pb (II)-CMHBH and 12.63x106 for Pb (II)-CMTSC. The standard deviation of the method in the determination of 2.59-μg ml- 1 of Pb (II) was 0.001 for CMHBH and 0.002 for CMTSC. The Relative standard deviation was 0.22% for Pb (II)-CMHBH and 0.52% for Pb (II)-CMTSC complex. First and second order derivative Spectophotometric methods were developed at max 450 nm and 470 nm for Pb (II)-CMHBH and at 440 and 460 nm for Pb (II)-CMTSC for the determination of Pb (II) which is more sensitive than the zero order method. The developed method has been used for the determination of Pb (II) in synthetic and natural samples. The results are in good agreement with the certified values.

Keywords: Pb (II), Spectrophotometry, Environmental samples, Micellar medium, CMHBH, CMTSC.