Department of Analytical and Environmental Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius, Lithuania A simple and rapid ion pair chromatographic method has been developed for the determination of thiocyanate. Separation was carried out on a 25 cm × 4.6 mm Ascentis C18 column (5 μm particle size) with a mobile phase containing 2 mmol/l tetrabutylammonium (TBA)-phosphate (pH 6.5) ...

The thermodynamic activities of ion pairs were measured el~ctrometrically in a series of aqueous mixtures of monoionic bentonite and the corresponding chlorides. Ion exchange membranes and Ag-AgC1 electrodes were used. The lyotropie order for the various cation species varied somewhat for two different preparations. The apparent relative escaping tendencies of the various cations did not corres...

In the present work, we have studied ion-pair states of matrix-isolated I(2) with vacuum-UV absorption and UV-vis-NIR emission, where the matrix environment is systematically changed by mixing Kr with Xe, from pure Kr to a more polarizable Xe host. Particular emphasis is put on low doping levels of Xe that yield a binary complex I(2)-Xe, as verified by coherent anti-Stokes Raman scattering (CAR...

We have studied the cluster structure of 1-butyl-3-methylimidazolium halide, bmimX (X = Cl, Br, I), in methanol solution by means of an electrospray mass spectrometer, which is specially designed for analysis of clusters isolated from solution. In positive ion mode experiments, the ratio of solvated bmim(+), bmim(+)(MeOH)(n) and ion-pair clusters, bmim(bmim(+)X(-))(m) was dependent on the count...

Over the past thirty years, a large number of macrocyclic receptors have been synthesized and evaluated for their abilities to bind cations. More recently, increased attention has been directed towards receptors for anions. Many of these synthetic receptors are uncharged molecules and operate in organic solvents. Under these conditions the target salts exist as associated ion-pairs which can hi...

The multitopic ion-pair receptor 2 is able to recognize and extract various cesium and potassium salts via three different ion recognition modes. Furthermore, it is capable of extracting and then releasing KNO(3)via ion-pair metathesis with CsClO(4), allowing KNO(3) recovery.

     A simple and sensitive extractive spectrophotometric method is described for determination of tropicamide. The method is based on the reaction of tropicamide and bromocresol green. The ion-paired colored complex was extracted with chloroform at pH 3. The extracted complex showed maximum absorbance at 423 nm. The complex was stable up to 2 days and obeyed Beer's law over the concentration r...

There is a growing demand for the separation and identification of short nucleic acid fragments, such as oligonucleotides. There were two main goals of the present investigation, namely, evaluation of the impact of stationary phase type and the influence of various ion-pair reagents on the retention behavior of oligonucleotides in ion-pair liquid chromatography. Three types of ion-pair reagents...

A novel counter-ion, N-methylimipramine, was synthesized and utilized in the separation of inositol phosphates by ion-pair chromatography. The structural identity of the counter-ion was documented by nuclear magnetic resonance spectroscopy. This counter-ion was capable of resolving inositol phosphates isocratically by reversed-phase high-performance liquid chromatography. Solvent polarity and i...