title: Wide range pH measurements using a single H(+)-selective chromoionophore and a time-based flow method.
abstract: A hydrophilic transparent triacetyl cellulose membrane was adopted as a pH optode by immobilizing highly selective and sensitive Nile blue indicator on the membrane. Contrary to the common procedure for determinations using optodes, in which a steady state response is measured, a new approach is introduced in which the dynamic response of the optode is used as the analytical signal. While in common procedures, pH optodes exhibit limited linear dynamic range (often 2-4 pH units only), it is shown that in a time-based flow method, an optode with only one acid-base indicator can be used for measurement in the pH range of 0-10. The procedure is simple, inexpensive and rapid.
authors.affiliation: Department of Chemistry, Faculty of Sciences, Shiraz University, Shiraz 71454, Iran.
authors.forename: Afsaneh
authors.initials: A
authors.lastname: Safavi
authors.forename: Abolfazl
authors.initials: A
authors.lastname: Rostamzadeh
authors.forename: Saeed
authors.initials: S
authors.lastname: Maesum