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...

We study the solvation and the association properties of ion pairs in aqueous dimethyl sulfoxide (DMSO) solution by atomistic molecular dynamics (MD) simulations. The ion pair is composed of two lithium and a single sulfonated diphenyl sulfone ion whose properties are studied under the influence of different DMSO concentrations. For increasing mole fractions of DMSO, we observe a non-ideal beha...

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...

A simple, rapid, cost-effective spectrophotometric method is developed to determine arsenic in ppm levels. The present study is based on the reaction of arsenate with acidified molybdate and vanadate to form a molybdovanadoarsenate complex. The heteropoly acid complex formed interacts with cationic dye, Rhodamine B resulting in pinkcoloured ion-pair complex whose absorbance is measured at 590 n...

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.