tea is the second most commonly consumed beverage world wide. tea ( camellia sinensis ) is a naturally rich source of fluoride. the quantity of fluoride intake is important in optimizing its dental caries-preventive role. intense concentration of fluoride in tea, can lead to excessive fluoride intake which may cause health problems in turn. the measurement of fluoride intake usually requires in...

A PVC membrane electrode based on 1-[({[(butylsulfunyl)carbothioyl]disulfanyl} carbothioyl)sulfanyl]butane as a suitable ion carrier for determination of lanthanum(III) ion was prepared. This electrode revealedsuch a good selectivity toward La3+ ion over a wide variety of other metal ions. Some experimental parametersuch as membrane composition, nature, and amount of plasticizer, the amount of ...

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 objective of this research is to find an economically attractive alternative method for hydrodesulfurization of petroleum fractions and to select a suitable adsorbent for this process.deep desulfurization of transportation fuels (gasoline, diesel, and jet fuels) is being mandated by governments and is also needed for future fuel cell applications. however, it is extremely difficult and cost...

an ion chromatography (ic) method for simultaneous determination of benzoic, salicylic and sorbic acids was developed. in this method the samples were purified by solid-phase extraction. the analytes were then eluted with methanol from c18 cartridge. the separation was performed on ion-exclusion column by an isocratic elution with 0.25 mmol /l sulfuric acid solution containing 20% (v/v) acetone...

in the present study, a simple and sensitive extractive spectrophotometric method is described for determination of buspirone. the method is based on the reaction of buspirone and bromocresol green. the ion-pair complex was quantitatively extracted into chloroform at ph 2.3 followed by spectrophotometric determination at 415 nm. the complex was stable up to 2 days and obeyed beer's law over the...

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...

Photocatalyst nanocomposites of ZnO/bentonite clay are synthesized by Solid-state ion exchange method. Ion exchange intercalation process of clays is used to incorporate the catalyst into the basal space of the layered structure of clays. The purpose of this study is to find a new method, which is focused on simplifying and saving time to prepare ZnO-bentonite composite with photocatalyst prope...