Adsorption of di-2-pyridyl ketone salicyloylhydrazone on silica gel: characteristics and isotherms.

The adsorption of DPKSH onto silica gel was investigated, at 25+/-1 degrees C and pH 1, 4.7 and 12. For the same DPKSH concentration interval, the minimum required time of contact for adsorption maximum at pH 4.

Adsorption of di-2-pyridyl ketone salicyloylhydrazone on Amberlite XAD-2 and XAD-7 resins: characteristics and isotherms.

The adsorption of DPKSH onto Amberlite XAD-2 (styrene resin) and XAD-7 (acrylic ester resin) has been investigated, at (25+/-1) degrees C and pH 4.7. The experimental equilibrium data were fitted to the Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) models.

Spectrophotometric flow injection methods for zinc determination in pharmaceutical and biological samples.

Zinc ions form a yellow complex with di-2-pyridyl ketone salicyloylhydrazone (DPKSH). This complex showed maximum absorption at 376 nm, and it was used to develop spectrophotometric flow injection methods for Zn(II) determination in different samples. Two types of flow systems were proposed.

Kinetic modeling of adsorption of di-2-pyridylketone salicyloylhydrazone on silica gel.

The kinetics of DPKSH (di-2-pyridylketone salicyloylhydrazone) adsorption onto silica gel has been investigated at (25+/-1) degrees C and pH 1 and 4.7. The kinetics of adsorption of DPKSH is discussed using three kinetic models, the first-order Lagergren model, the pseudo-second-order model, and the intraparticle diffusion model.

Henry's Law as a Limit for an Isotherm Model Based on a Statistical Mechanics Approach.

The fundamental integral equation for isotherms derived from statistical mechanics was applied to the analysis of adsorption under low concentrations (or pressures). The model considers adsorption on an energetically heterogeneous surface characterized by an energy distribution function in the semiexponential form N(Q) = (m/RT)e-mQ/RT and by the individual adsorption of each site obeying the Langmuir isotherm. The expression derived guarantees a linear relationship of the covering degree, q, and the concentration, C, that is, q = HC (Henry's law), under the condition of low values of concentration.