the quenching of quinine fluorescence intensity in the presence of some anions in aqueous solution at ambient temperature has been investigated. the quenching is found to be collisional or dynamical in nature. this study reveals the order of two groups of quencher: nai > nabr > nacl > naf and k2cr2o7 > kmno4 >na2so4 > naclo3. increasing anion size in the both groups leads to an  increase in the...

With a mean precipitation rate, much lower than that of the world, Iran is among the countries that face severe water challenges. The present study has dealt with the evaluation of hydrochemistry of Faryab spring water in Hormozgan Province, Iran. Four different composite water samples have been analyzed to detect major anions, cations, total dissolved solids, electrical conductivity, pH, and s...

The kinetics and mechanisms of the substitution reactions of trans-[Co(en)2CNCl]+ with unidentate anions,  , CN¯, I¯,  , Br¯ and SCN¯ in 60% v/v DMF-H2O binary solvent at 40.0±0.2 °C were studied spectrophotometrically. An Id mechanism was assigned for the replacement of chlorine by , CN¯ and I¯, an Ia one for...

a rapid, sensitive and versatile kinetic method is presented for the simultaneous spectrophotometric determination of iodide and iodate by partial least-squares regression (pls) using original and derivate data named as absorbance and rate data. the method is based on the catalytic effect of the cited anions on the reaction rate between ce(iv) and as(iii) in 2 mol l?1 sulfuric acid medium. the ...

A PVC-based membrane containing cerium phosphate was developed. Unlike the cerium phosphate itself that acts as a cation exchanger, the membrane exhibited anion-exchange properties. Therefore, the utility of this compound as a sensory element for detection of molybdate ions was pursued. The response of molybdate selective electrode based on this membrane was perfectly linear in the concentr...

Four novel receptors were designed and synthesized for colorimetric detection of F− ions. The introduction of four electron withdrawing groups into the backbone of the receptors makes the two phenolic groups efficient hydrogen bonding sites. The binding properties of receptors with anions were examined for the first time by UV–Vis, 1H NMR and fluorescence spectroscopies. The addition of F− resu...

a series of amino derivative of 1-indene and 9-fluorene have been synthesized from their corresponding iminium salt, generated in situ in the concentrated ethereal lithium perchlorate solution, and 1-indenyl or 9-fluorenyl anions. the yields of the reactions depend on the kind of anion. addition of 1-indeny anion to the iminium salt gives the amino derivative of 1-indene, while addition of fluo...

The quenching of quinine fluorescence intensity in the presence of some anions in aqueous solution at ambient temperature has been investigated. The quenching is found to be collisional or dynamical in nature. This study reveals the order of two groups of quencher: NaI > NaBr > NaCl > NaF and K2Cr2O7 > KMnO4 >Na2SO4 > NaClO3. Increasing anion size in the both groups leads to an  increase in the...

unmodified zeolites show little affinity for anions due to the fact that their surfaces are negatively charged. however modification of zeolites with amines turns their negative surface charge to positive and creating higher adsorption capacity for anions. in this study, polyaniline-clinoptilolite composite was prepared by polymerization of anilinium on the surface of zeolite. the composite was...