The development of an optical pH sensor based on immobilization of quinizarin (1,4-dihydroxyanthraquinone) on a triacetylcellulose membrane was described. The resulting membrane exhibited fast color change from yellow to violet, while changing the pH in alkaline region. The immobilized quinizarin showed a broader dynamic range from (pH 9.4-11.4) with respect to free form (pH 8.8-10.4). The sens...

An optode was designed for an indirect determination of ascorbic acid by using neocuproine, which has been coated on transparent triacetylcellulose film as a membrane. The proposed method is based on the oxidation of ascorbic acid to dehydroascorbic acid with the Cu(II) and neocuproine reagent. The increase in the absorbance value of the optode at the maximum wavelength of 455 nm was related ...

An inexpensive and fast vanadium [(IV), (V)] speciation method was performed by using optical chemical sensor that incorporates lipophilized calmagite (Cal) with cetyl pyridinium chloride (CPC) as a suitable ligand on triacetylcellulose membrane in aqueous solutions prior to UV-Vis spectrometric determination. Absorbance decrease of the optode in pH 6 at 490 nm depended on the V(V) ion concentr...

A new ammonia optical sensor was designed using bis(acetylacetoneethylendiamine)tributylphosphin cobalt(III) tetraphenylborate complex, coated on transparent triacetylcellulose film as membrane. The change in the absorbance of the optode at the maximum wavelength of 408 nm was related to ammonia concentration in aqueous samples. A buffer solution with a pH of 9 (sodium borate-HCl) was used. The...

This study has been done to investigate the effect of mouth rinses of chlorhexidine on the development of dental plaque in man. Twenty patients participated in this study (from nineteen years old to twenty-six years old. Ten male and ten female). On the lingual surfaces of mandibular anterior teeth , triacetylcellulose film was tight with 4-0 silk suture. On the experimental group, L-S solution...

a method is described by which it is possible to determine the high barrier to ring inversion and hindered rotation by neat racemization of optically active compounds when the racemization is caused by ring inversion or hindered rotation. the method is based preparation of sufficiently pure enantiomers, mainly by chromatography on swollen microcrystalline triacetylcellulose (tac). by this techn...

A selective optical sensor based on immobilization of Eriochrome Cyanine R for the determination of Al(III) ions in aqueous solution has been developed. The method is based on the spectrophotometric measurement of complex Eriochrome Cyanine R-aluminium at 537 nm. The sensing membrane is made of a triacetylcellulose film containing Eriochrome Cyanine R colorimetric reagent immobilized as an ion ...