Characterization of Surface Modification, Thermal Stability, and Metal Selectivity Properties of Silica Gel Phases-Immobilized Dithiocarbamate Derivatives

• Published in: Journal of liquid chromatography & related technologies Vol. 27; no. 11; pp. 1711 - 1727
• Main Authors: Mahmoud, Mohamed E., El-Essawi, Mohyi M., Fathallah, Eiman M. I.
• Format: Journal Article
• Language: English
• Published: Colchester Taylor & Francis Group 01.01.2004; Taylor & Francis
• Subjects: Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Dithiocarbamate; Exact sciences and technology; Metal selectivity; Other chromatographic methods; Silica gel; Surface modification; Thermal stability; Electron impact; Divalent metal Ions; TDS; Organic dithiocarbamate; Chromatographic retention; Cadmium II Ions; Immobilization; Secondary ion mass spectrometry; Liquid chromatography; Selectivity; Surface analysis; Thermal stability; Surface treatment; Heavy metal; Transition metal Ions; Silica gel; Copper II Ions; Mass spectrometry; Mercury II Ions; Stationary phase
• ISSN: 1082-6076; 1520-572X
• DOI: 10.1081/JLC-120037366

Carbon disulphide was used to modify the surface of silica gel phases containing amine moieties for the formation of four phases-immobilized dithiocarbamate derivatives (I-IV). Characterization of the surface modification by the organic modifier was accomplished by several means of instrumental analysis. These include infrared, secondary ion mass spectrometry (SIMS), as well as, thermal desorption analysis for determination of the surface coverage values (1.051-1.501 mmol g −1 ). The thermal stability and structure characterization of the modified silica gel phases (I-IV), along with their mercury(II) adducts, were studied and evaluated on the basis of electron impact mass spectrometric analysis (EI-MS). The results of this study proved higher thermal stability characters incorporated into the metal adduct compared to the free silica gel phase. The selectivity properties incorporated into the modified silica gel phases for binding and interaction with a series of bi- and trivalent metal ions were studied and evaluated by determination of the distribution coefficient and separation factor. The results of these evaluation processes were found to point out the higher selectivity and preference of these four phases for binding with mercury(II), copper(II), and cadmium(II) compared to other metal ions.