Effects of Residual Silanol on Solid Phase Extraction of Organic Compounds to Octadecylsilyl Silica.

Batchwise equilibrium study was carried out on the retention of nonpolar and polar organic compounds to octadecylsilyl (ODS) silicas of different properties at atmospheric pressure. While nonpolar compounds were retained only by distribution on the ODS phase, polar compounds were retained by both distribution and Langmuir-type adsorption on residual silanol. Retention on ODS silica with more silanol proceeded at a higher rate than retention on ODS silica with less silanol and was reversible on this solid phase extraction time-scale.

Roles of Residual Silanol in Solid Phase Extraction of Copper to Octadecylsilyl Silica in the Presence of Acetylacetone.

Batchwise studies have demonstrated that the retention of acetylacetone (Haa) from an aqueous phase in non-endcapped octadecylsilyl (ODS) silica with silanol intentionally left (NEC) is stronger than the retention in endcapped ODS silica under ambient pressure, due to the enhanced wettability and the contribution of adsorption to silanol (-SiOH) as well as of the distribution into the ODS phase. Equilibrium analysis on solid phase extraction (SPE) of copper ion with Haa to NEC has indicated the adsorption of 1:1 species by the proton replacement reaction with silanol to give [-SiOCu(aa)] at relatively low Haa concentrations and the adsorption of [Cu(aa)] to silanol, as well as the distribution of [Cu(aa)] into the ODS phase. These adsorbed and distributed species of the same composition could be differentiated by ESR spectroscopy.

Perchlorate Selectivity of Anion Exchange Resins as Evaluated Using Ion-Selective Electrodes.

The selectivity coefficients reported for perchlorate of the high selectivity on anion exchange resins (AXRs) have not been consistent with one another. Possible errors by the unique use of four parameters (concentrations of two anions in two phases) were experimentally verified. The concentrations of perchlorate buffered at low levels (10 - 10 mol L) by two forms of AXRs were successfully determined by potentiometry with a perchlorate ion-selective electrode.

Erratum: Analytical Sciences, 2016, Vol. 32, No. 3, p. 343, Enhanced Retention of Chelating Reagents in Octadecylsilyl Silica Phase by Interaction with Residual Silanol Groups in Solid Phase Extraction of Divalent Metal Ions.

On page 343, the abstract, the second line,with which octadecylsilyl silica (ODS), was impregnated with was studiedshould readwith which octadecylsilyl silica (ODS) was impregnated, was studied.

Enhanced Retention of Chelating Reagents in Octadecylsilyl Silica Phase by Interaction with Residual Silanol Groups in Solid Phase Extraction of Divalent Metal Ions.

Solid-phase extraction (SPE) of divalent metal ions with a lipophilic and potentially divalent hexadentate chelating reagent (H2L), with which octadecylsilyl silica (ODS), was impregnated with was studied to gain more insight into and develop the potential of this methodology. This is the first time to demonstrate that this reagent as well as other common nitrogen-containing reagents were retained both by adsorption due to hydrogen bonding between nitrogen atoms of the reagent and residual silanol groups in the ODS phase and by simple distribution into the hydrophobic space. An appreciably large amount of this reagent could be retained by the adsorption mechanism even with a relatively thin loading solution.

Liquid-liquid extraction of divalent transition metal ions with a novel bis-β-ketoester extraction reagent.

Solvent extraction is a very effective method for the separation of metal ions. N,N'-bis(2-hydroxy-phenylmethyl)-N,N'-bis(2-pyridylmetyl)-1,2-ethanediamine derivatives have been researched for solvent extraction of metal ions. In this study.