Development of potentiometric sensors for the selective determination of UO22+ ions

The construction and performance characteristics of poly(vinyl chloride) membrane electrodes for uranyl ions based on dibutyl butyl phosphonate (L1) and di-n-octyl phenyl phosphonate (L2) as ionophores, are reported. The optimized membrane electrodes based on L1 and L2 exhibited a Nernstian response for uranyl ions over a concentration range of 5.0 × 10−6–1.0 × 10−1 and 5.5 × 10−5–1.0 × 10−1 mol L−1in the pH range 2.1–3.4, with slopes of 28.6 and 29.7 mV decade−1, respectively. The optimized electrodes exhibit good selectivity for UO22+ ions over a wide variety of other metal ions. The electrodes exhibit a fast dynamic response of ~30 s. The developed sensors were used for potentiometric determination of uranyl ions concentration in different real samples and the obtained results agreed well with those obtained employing inductively coupled plasma optical emission spectrometer.