The methods used to facilitate the supercritical fluid extraction (SFE) of polar and ionic compounds are based on two general principles, either increasing the polarity of the supercritical fluid (SF) (usually CO,) used as extractant or reducing the polarity of the analytes to be leached from the solid matrices. Changes in the pressure and temperature of the SF, the use of SFs more polar than C...

In recent years, ionic liquids have been used in pharmaceutical processes. Therefore, having a deep insight into the ion association behavior of ionic liquids in the presence of a drug is of particular importance. So, in this work, the molar conductivities of the ionic liquids, 1-alkyl-3-methylimidazolium bromide, [CnMIm]Br (n = 4, 6 and 8) in various concentrations of aspirin (ASA) ...

The cobaltabisdicarbollide anion is used as a new material able to generate an ion-pair complex used for PVC membrane ion selective electrodes.

A simple and reproducible spectrophotometric method has been developed for the determination of valacyclovir in bulk and pharmaceutical dosage forms. The proposed method was based on the formation of chloroform extractable complex of valacyclovir with wool fast blue. The absorbance of the extractable ion pair complex is measured at the wavelength of maximum absorbance 585 nm against the reagent...

Two simple visible spectrophotometric methods are developed and validated for the quantification of modafinil using 1,2-naphthoquinone-4-sulphonic acid (NQS method) and 2,4-dinitrophenol (DNP method) as analytical reagents. The NQS method involves the reaction of modafinil with 1,2-naphthoquinone-4-sulphonate in alkaline medium at room conditions to form a yellow colored product exhibiting maxi...

The solubility of CdF2 in the mixed solvent (water(1)+ethanol(2)) with mass fraction, W1 = 0.9,was determined by using solvent evaporating method in the presence of various concentrations(0.100, 0.200, 0.300, 0.400, 0.500, 0.600, 0.800 and 1.500 mo1.1)) of NaCI at 25°C. The values ofsolubility and solubility product constant of CdF2 in the mixed solvent were evaluated at zero ionicstrength upon...

The extraction and separation of copper(II), zinc(II), cobalt(II), and cadmium(II) were investigated. Both copper(II) and zinc(II) formed ammine-complexes, while cadmium(II) and cobalt(II) formed hydroxide precipitates in an ammonia medium. By the addition of sodium dodecylsulfate (SDS), a copper(II) complex formed an ion-pair (copper-ammine-DS), which was extracted into the SDS phase. However,...