Development of a Novel Automatic Potentiometric System for Determination of Selenium and Its Application in Pharmaceutical Formulations and Anodic Slime

Abstract

Poly(vinyl chloride) polymeric membrane sensors containing Sn(IV) phthalocyanine dichloride (SnPC) and Co(II) phthalocyanine (CoPC) as novel electroactive materials dispersed in o-nitrophenyl octylether (o-NPOE) as a plasticizer are examined potentiometrically with respect to their response toward selenite (SeO 3 2À ) ions. Fast Nernstian response for SeO 3 2À ions over the concentration ranges 7.0 Â 10 À6 -1.0 Â 10 À3 and 8.0 Â 10Àl at pH 3.5 -8.5 with lower detection limit of 5.0 Â 10 À6 and 8.0 Â 10 À6 mol L À1 and calibration slopes of À 25.4 and À 29.7 mV decade À1 are obtained with SnPC and CoPC based membrane sensors, respectively. The proposed sensors reveals by the modified separate solution method (MSSM) a good selectivity over different anions which differ significantly from the classical Hofmeister series. A segmented sandwich membrane method is used to determine complex formation constants of the ionophores in situe in the solvent polymeric sensing membranes. Membrane incorporating CoPC in a tubular flow detector is used in a two channels flow injection set up for continuous monitoring of selenite at a frequency of ca. 50 samples h À1 . Direct determination of selenium in pharmaceutical formulations and anodic slime gives results in good agreement with data obtained using standard ICP method.

Development of a dual-analyte fluorescent sensor for the determination of bioactive nitrite and selenite in water samples

“…Selenium and nitrite are two natural bioactive compounds which behave as a double-edged sword, since show beneficial effects for health at low levels but are toxic at higher doses. In the case of selenium, it is an essential nutrient of fundamental importance for animals and humans, however, it is highly toxic at levels above a narrow range of that considered a health level in the human diet; daily consumption of less than 0.05-0.1 mg/kg of body weight will result in selenium deficiency while levels that exceed about 1 mg/kg are considered toxic [13]. The bioavailability and toxicity of selenium depend to a large extent on its chemical form.…”

CASSCF/CASPT2 Calculation of the Low-Lying Electronic States of the CH3Se Neutral Radical and Its Cation

“…Due to their potential importance in atmospheric, environmental, and biological chemistry, selenium and its compounds have drawn considerable attention. − As the simplest organic selenium species, the CH 3 Se radical is suggested to be an important intermediate in most chemical reactions of both dimethyl selenide and dimethyl diselenide, and it has to be included in the global selenium cycle. , Therefore, the theoretical investigation of the CH 3 Se radical is very important work. The most thorough studies have been reported on the excitation spectroscopy and photoelectron spectroscopy of its homologous radicals, CH 3 O and CH 3 S;, − however, much less is known about CH 3 Se.…”

Application of phthalocyanines in flow- and sequential-injection analysis and microfluidics systems: A review

“…No interferences were caused by most common anions normally associated with azide ion. The development of a novel FIA automatic potentiometric system for determination of selenium and its application in pharmaceutical formulations and anodic slime were also presented[130]. Poly(vinyl chloride) polymeric membrane sensors containing Sn(IV) phthalocyanine dichloride (SnPc) and Co(II) phthalocyanine (CoPc) as novel electroactive materials dispersed in o-nitrophenyl octylether (o-NPOE) as a plasticizer were examined potentiometrically with respect to their response .…”