N. Fatima

Thin-Layer Chromatography of Metal Ions in Formic Acid Medium on Impregnated and Unimpregnated Silica Gel G: Semiquantitative Determination of Fe3+, Cd2+, Th4+, Al3+, Zn2+, UO2+ 2, VO2+, Ce4+, and Ni2+

Abstract The adsorption behavior of metal ions in the formic acid-sodium formate system using unimpregnated as well as impregnated silica gel G as thin layers has been studied. A remarkable result of this study is the dramatic selectivity of impregnated silica gel G thin layers when compared to the corresponding unimpregnated silica gel G thin layers. This impregnation effect provides us with a new adsorbent phase which is sufficiently stable in the formic acid-sodium formate medium. Some important ternary separations have been achieved on silica gel G thin layers. Al3+, Ni2+, Fe3+, and Pb2+ have been qualitatively separated from mixtures of other ions. Cu2+ has been selectively separated on impregnated silica gel G thin layers. The semi-quantitative determination of nine metal ions on impregnated silica gel G layers has also been attempted.

Reverse Phase Thin-Layer Chromato-Graphy of some Metal Ions on Butyl-Amine Impregnated Silica Gel G in Formic Acid Medium

Abstract Reversed phase thin layer chromatography of metal ions have been performed on s-butylamine and t-butylamine impregnated silica gel thin layers in formic acid and sodium formate systems. Separation potential of impregnated silica gel thin layers was explored. Impregnated silica gel layers were found to be more selective (strongly sorbing) than unimpregnated silica gel chromo-toplates. Several important binary and ternary separations were achieved on impregnated thin layers.

Determination of microquantities of mercury(II) with preliminary thin-layer chromatographic separation from mercury(I), lead(II), nickel(II), and copper(II) on acid-treated silica gel layers: recovery of mercury(II) from river waters and industrial wastewaters

Thin-layer chromatography in combination with spectrophotometry has been applied for the separation and estimation of Hg(II) using silica gel layers impregnated with 2% oxalic acid as stationary phase with an ethyl acetate:acetone:formic acid:water (8:7:4:1) solvent system. Separation of Hg(II) from Hg(I) and of Th4+ from UO22+ is not affected by the presence of common anions in the sample solution. Hg(II) has been successfully separated from Ni(II), Cu(II), and Pb(II) over a wide range of pH (0.5–7.0) of sample solution. An attempt has been made to recover Hg(II) from rivers and industrial wastewaters.

New inexpensive and selective sorbent phases for rapid thin layer chromatographic analysis of metal ions

Abstract New sorbent phases have been developed by impregnating silica gel G with different inorganic salts for the analysis of metal ions by thin layer chroma to graphy in carboxylic acids media. Thin layers prepared from silica gel G impregnated with ammonium chloride or barium nitrate show the unusual selectivity towards metal ions in comparison to the thin layers prepared from plain silica gel G or silica gel impregnated with silver nitrate or aluminium nitrate. Many qualitative separations

A Novel Quantitative Separation of Cr(III) from Numerous Metal Ions on β-Stannic Arsenate Thin Layers in DMSO—HCI Systems

Abstract This paper deals with the thin-layer chromatography of metal ions on β-stannic arsenate using dimethylsulfoxide solvent system. A novel quantitative separation of Cr(III) has been developed on these thin layers. The method is precise and accurate and can be applied for the quantitative separation of Cr(III) from mixtures containing Cu, Nb, Ta, Ce, Ni, Co, Al, Zn, Mn, Th, La, Cd, and Pt. A mechanism dealing with this separation is also been presented based on the kinetic inertness of Cr(III), the properties of DMSO, and the selectivity of β-stannic arsenate.

TLC separation of microgram quantities of iron(II) from milligram quantities of iron(III)

Abstract A TLC method has been developed for the separation of microgram quantities of Fe(II) from milligram quantities of Fe(III) by using formic acid-butanol-ethyl methyl ketone as mobile phase. The separation is not effected by the presence of chloride, bromide, sulfate, sulfite, acetate and phosphate ions. Good separation was achieved when the pH of the sample solution was kept near to 1.0.

Thin-Layer Chromatography of Metal Ions on Stannic Arsenate: Quantitative Separation of Hg(II) from Cd(II), Zn(II), and Cu(II)

Abstract Stannic arsenate thin layers (0.25 mm) have been applied for the chromatographic studies of 42 metal ions without using any binder. As a result, some important binary separations, such as Cd-Sb, V-Nb, V-Ta, Ni-Fe, Pd-Nb, Hg-Pb, and Pb-Mo, have been performed. Quantitative separation of Hg from Cd, Zn, and Cu has also been made by this technique. The study has been found to give reproducible results on refluxed and nonrefluxed samples of stannic arsenate used simultaneously.

Separation of microgram quantities of cadmium(II) from milligram quantities of zinc(II) and of copper(II) from nickel(II) and cobalt(II) with aqueous sodium formate-halogen anion systems

Abstract The chromatographic behavior of certain cations on silica gel layers with aqueous sodium formate-halogen anion systems has been studied. Several important separations in different solvent systems have been achieved. The effect of various important factors, such as sample concentration, eluent concentration, pH of salt solution, pH of mobile phase, and the presence of anions in the sample solution, on the separations of Cd2+ from Zn2+ and of Cu2+ from Ni2+, Co2+, and Cd2+ was examined.

Solid-phase color reaction of p-toluidine and diphenylamine for the selective detection of some nitro compounds

Capillary solid-state spot tests for some nitro compounds with p-toluidine and diphenylamine have been performed to achieve selective detection of nitro compounds. An attempt has been made to enhance the selectivity of the test by using a glass wool plug between the reactants in the glass capillary.

Chromatography of Some Metal Ions on Silica Gel Thin Layers in Butanol-Formic Acid Media

Abstract Chromato graphic behaviour of some metal ions on silica gel thin layers has been studied in butanol—formic acid media. The results have been compared with those obtained in aqueous formic acid medium. Many important and analytically difficult separations have been achieved. Some thin layer chromato graphic parameters for the separation of Vo2+ from numerous metal ions using 20.0 M formic acid in butanol have been determined.