Poly(vinyl chloride)-membrane ion-selective bulk optode based on 1,10-dibenzyl-1,10-diaza-18-crown-6 and 1-(2-pyridylazo)-2-naphthol for Cu2+ and Pb2+ ions

An ion-selective bulk optode (ISBO) for sensing Cu2+ and Pb2+ ions based on plasticized poly(vinyl chloride) containing 1,10-dibenzyl-1,10-diaza-18-crown-6 (DBzDA18C6) as ionophore and 1-(2-pyridylazo)-2-naphthol (PAN) as chromoionophore was prepared. The effects of DBzDA18C6/PAN and NaTPB/PAN mole ratios on the response behavior of the ISBO were investigated. The ISBO membrane shows enhanced selectivities for Cu2+ (at 530 nm) and Pb2+ (at 467 nm) over alkali, alkaline earth and other transition metal ions. The optical selectivity coefficients were measured using the separate solution method (SSM) in the two corresponding wavelengths at pH = 5. The detection limit for Cu2+ and Pb2+ are 3.2 x 10(-7) and 1.0 x 10(-8) M, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.