Hydrogen ion-selective poly(vinyl chloride) membrane electrode based on a p-tert-butylcalix[4]arene-oxacrown-4.

A hydrogen ion-selective poly(vinyl chloride) (PVC) membrane electrode was developed using p-tert-butylcalix[4]arene-oxacrown-4 as ionophore. Apart from the ionophore, plasticisers and lipophilic anions were blended, in various proportions, with PVC in tetrahydrofurane and mixtures so prepared were poured onto glass surfaces to form the membrane. 2-Nitrophenylpentylether has proved to be the best alternative as plasticiser and the lipophilic anions tried have turned out to have an adverse effect on the pH response.

Spectrofluorimetric assay of ciprofloxacin hydrochloride in tablets.

Objective: To describe the spectrofluorimetric method for the determination of ciprofloxacin hydrochloride in tablets under optimum conditions.

Study Design: Examination by spectrofluorimetry.

Results: The wavelengths of excitation and emission were 290 and 450 nm, respectively.

Hydrogen ion-selective poly(vinyl chloride) membrane electrode based on a calix[4]arene.

A hydrogen ion-selective poly(vinyl chloride) membrane electrode was constructed using 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetracyanomethoxycalix[4]arene as a neutral carrier. The electrode showed an apparent Nernstian response in the 2-11.5 pH range with a slope of 54.