Benzoate ion-selective electrode with improved selectivity and reproducibility for benzoate determination in medicinal syrups

• Type: Article in International Scientific Journal
• Date: 1996

Authors

Lima, JLFC (Author) FFUP; Montenegro, MCBSM (Author) FFUP; Sales, MGF (Author) Other

Journal

Title: Mikrochimica Acta

Vol. 124

Pages: 35-41

ISSN: 0026-3672

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 12 Citations

Scopus - 10 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-001-FF6

DOI: 10.1007/bf01244954

Abstract (EN): This paper describes the construction and evaluation of a benzoate anion selective electrode with enhanced working characteristics, namely reproducibility and selectivity, to be used in medicinal syrups analysis by direct potentiometry. The electrode, without an internal reference solution, was prepared with a PVC membrane, based on bis(triphenylphosphoranylidene) ammonium benzoate as ion-exchanger, dissolved in 2-nitrophenyl octyl ether as mediator solvent and 4-t-octylphenol as additive. The characteristics of the electrodes were evaluated in sodium benzoate solutions with adjusted ionic strength and showed a linear response in the range 10(-2)-2 x 10(-4) mol dm(-3) with a slope of 54.7 +/- 0.5 mV/decade and a reproducibility of +/- 0.2 mV/day for solutions with pH 6.3. The potentiometric selectivity coefficients were determined for some possible interfering species and showed that the electrodes prepared with the additive had good selectivity, especially over iodide and nitrate, when compared with those without any additive. The electrodes were used for benzoate determinations in several medicinal syrups by direct potentiometry. The results gave recovery values in the range 98.3-104.6%.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7