Monosegemented flow potentiometric titration for the determination of chloride in milk and wine

• Autor(a) principal: Vieira,Jonas A.
• Data de Publicação: 2003
• Outros Autores: Raimundo Jr.,Ivo M., Reis,Boaventura F., Montenegro,M. Conceição B.S.M., Araújo,Alberto N.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532003000200012
• topic: potentiometric titration; monossegmented flow; multicommutation; ion selective electrode; chloride in milk; chloride in wine

An automated flow potentiometric titration procedure for the determination of chloride in milk and wine exploiting the monosegmented flow approach is described. The flow network was designed based on a six-way solenoid valve, controlled by a microcomputer running software written in VisualBasic 3.0, allowing selection of the titration conditions. An Ag2S tubular electrode selective for Cl- and a conventional Ag/AgCl electrode were employed as indicator and reference, respectively. An algorithm based on the potential difference between two subsequent titrant additions was developed, allowing to reach the end point in less than 10 attempts, with a precision better than 1.0%. The proposed system was evaluated by determining chloride in milk and wine, using a standard AgNO3 solution as titrant. Accuracy was ascertained by comparing the results with those obtained using the AOAC procedure. No significant difference at a 95% confidence level was observed.