Determination of Cr super(3) super(+) ions in biological and environmental samples by a chromium(III) membrane sensor based on 5-amino-1-phenyl-1H-pyrazole-4-carboxamide

• Published in: Desalination Vol. 249; no. 2; pp. 560 - 565
• Main Authors: Zamani, HA, Rajabzadeh, G, Masrornia, M, Dejbord, A, Ganjali, M R, Seifi, N
• Format: Journal Article
• Language: English
• Published: 15.12.2009
• Subjects: Biological; Carriers; Cations; Chromium; EDTA; Electrodes; Sensors; Waste water
• ISSN: 0011-9164
• DOI: 10.1016/j.desal.2009.01.023

A highly Cr super(3) super(+)-selective ionophore, based on 5-amino-1-phenyl-1H-pyrazole-4-carboxamide (APC) as a carrier, was synthesized in order to obtain a Cr super(3) super(+) ion-selective electrode. The demonstrated characteristics of the sensor included a linear dynamic range between 1.0x10 super(-) super(6) and 1.0x10 super(-) super(1)M with a near Nernstian slope of 19.6+/-0.4mV per decade, a detection limit of 5.3x10 super(-) super(7)M, a very good selectivity for Cr super(3) super(+) over other cations in a wide pH range (3.2-6.3). Furthermore, the newly-designed electrode presented a fast response time of 10s with a lifetime of at least 2months indicating no considerable potential divergence. The sensor accuracy was investigated by the potentiometric titration of a Cr(III) solution with EDTA as well as the monitoring of Cr(III) in mixtures of three and five different ions. As a result, the developed sensor provided satisfactory results after its application in the Cr super(3) super(+) determination in biological samples (urine and synthetic plasma) and also in wastewater of chromium electroplating industries.