Heterogeneity of Cd(II)-Macromolecule Systems: A Potentiometric Study

✍ Scribed by Roger Serra; Francesc Mas; José Manuel Díaz-Cruz; Cristina Ariño; Miquel Esteban

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 123 KB
• Volume: 12
• Category: Article
• ISSN: 1040-0397
• DOI: 10.1002/(sici)1521-4109(20000101)12:1<60::aid-elan60>3.0.co;2-o

✦ Synopsis

The complexation of Cd(II) with polymethacrylic acid (PMA) and humic acid (HA) has been studied potentiometrically with a Cd-ISE at constant pH and ionic strength. Experimental data have been analyzed qualitatively by means of Scatchard plots to see the heterogeneity of the system and to predict the number of different functional groups. A quantitative description of the complexation behavior has been given by ®tting the binding curves to a Freundlich isotherm which provides a global characterization of the complexation process. The results obtained suggest an homogeneous behavior for the Cd(II)-PMA system and an heterogeneous one for the Cd(II)-HA system. Conditional intrinsic stability constants have been obtained for both systems.