Inorganic anions were separated on a reversed-phase stationary phase dynamically modified with crown ether as a selector in capillary ion chromatography. The eluent contained crown ether, acetonitrile and a salt. Free and cation-trapped crown ether molecules in the eluent were adsorbed on a hydrophobic stationary phase such as triacontyl-functionalized silica (C30). The eluent cations trappe...

Ion association of the ionic liquid [bmim][Cl] in acetonitrile and in water was studied by dielectric spectroscopy for salt concentrations c r 1.3 M at 298.15 K and by measurement of molar electrical conductivities, L, of dilute solutions (c r 0.006 M) in the temperature range 273.15 t T/K r 313.15. Whilst acetonitrile solutions of [bmim][Cl] exhibit moderate ion pairing, with an association co...

The electrogenerated chemiluminescence (ECL) of Ru(dp-bpy):+ (dp-bpy = 4,4’-diphenyl-2,2’bipyridine) and Ru(dp-phen):+ (dp-phen = 4,7-diphenyl-l,lO-phenanthroline) in acetonitrile and aqueous solutions was studied. The diphenyl-substituted compounds produced a more intense emission than the nonsubstituted Ru(bpy):+ Ru(dp-phen):+ m acetonitrile. The ECL efficiencies, dECL, of Ru(dp-bpy):+ and we...

The condensation of benzylamine with glyoxal leads to Hexabenzylhexaazaisowurtzitane (HBIW) in acetonitrile solvent with citric acid as a green catalyst under both conventional stirring and ultrasonic irradiation conditions. The influence of four variables, including the amount of catalyst, solvent, reaction time and ultrasonic power, on the reaction yield was investigated. The results showed t...

The distribution constants of amitraz and its three main metabolites (DMFF, DMF, DMA) for water–organic solvent (n-hexane, toluene, dichloromethane, chloroform) extraction systems were estimated. Based on the analysis substances in studied systems, it was established that dichloromethane is optimal choice liquid-liquid method development their simultaneous determination honey. Amitraz stability...

This study was developed and validated for the determination of oxyclozanide residue concentrations in beef and commercial milk, using high-performance liquid chromatography system. Oxyclozanide was successfully separated on a reverse phase column (Xbridge-C(18), 4.6×250 mm, 5 µm) with a mobile phase composed of acetonitrile and 0.1% phosphoric acid (60:40, v/v%). This analytical procedure invo...

The absorption and fluorescence spectra of phenylcoumarin and cyanophenylbenzocoumarin-3carboxylates 6a-f and 9a-e have been investigated in chloroform, acetonitrile and ethanol. The substituting groups with varying electron donating ability such as N,N-diethyl amine and morpholine at 7-position, in phenylcoumarin-3-carboxylate 6a-f exhibits fluorescence at a longer wavelength i.e. 420-460 nm i...

A colorimetric pyrophosphate assay based on the formation and reduction of the 18-molybdopyrophosphate ([(P2O7)Mo18O54](4-)) anion in an acetonitrile-water mixed solvent was modified and improved. The [(P2O7)Mo18O54](4-) anion is precipitated from the acetonitrile-water solution containing MoO4(2-) and HCl, and is re-dissolved in neat acetonitrile or propylene carbonate. This separation process...

synthesis and cation selectivity of 25, 27, dipropoxy-26, 28, di-propoxy 5, 11, 17, 23, ptert-butyl calix[4]arene are studied in acetonitrile solution. the stability constants of differentcomplexes of calixarene (as a ligand) with alkali metal cations are determined at 25 °c by usingspectrophotometric technique.on the basis of calculations, complexation of calixarene with cs+and li+ are more fa...