Flow-Injection Potentiometric Method for the Routine Determination of Chloride: Application to Bread Analysis

• Type: Article in International Scientific Journal
• Date: 2010

Authors

Sofia A A Almeida (Author) Other; Tania S C R Rebelo (Author) Other; Ana M Heitor (Author) Other; Beatriz B P P Oliveira (Author) FFUP; Goreti G F Sales (Author) Other

Journal

Title: Current Analytical Chemistry

Vol. 6 No. 3

Pages: 277-287

ISSN: 1573-4110

Publisher: Bentham Science

Indexing

ISI Web of Knowledge - 1 Citation

Scopus - 1 Citation

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-003-273

Abstract (EN): Bread is consumed worldwide by man, thus contributing to the regular ingestion of certain inorganic species such as chloride. It controls the blood pressure if associated to a sodium intake and may increase the incidence of stomach ulcer. Its routine control should thus be established by means of quick and low cost procedures. This work reports a double-channel flow injection analysis (FIA) system with a new chloride sensor for the analysis of bread. All solutions are prepared in water and necessary ionic strength adjustments are made on-line. The body of the indicating electrode is made from a silver needle of 0.8 mm i.d. with an external layer of silver chloride. These devices were constructed with different lengths. Electrodes of 1.0 to 3.0 cm presented better analytical performance. The calibration curves under optimum conditions displayed Nernstian behaviour, with average slopes of 56 mV decade(-1), with sampling rates of 60 samples h(-1). The method was applied to analyze several kinds of bread, namely pao de trigo, pao integral, pao de centeio, pao de mistura, broa de milho, pao sem sal, pao meio sal, pao-de-leite, and pao de agua. The accuracy and precision of the potentiometric method were ascertained by comparison to a spectrophotometric method of continuous segmented flow. These methods were validated against ion-chromatography procedures.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11