Novel potentiometric carbon paste electrodes for trace detection of uranyl(II) ions in petroleum water samples

Abstract

Two different phosphine sulfide derivatives have been explored as electroactive materials to modify carbon paste electrodes for the accurate detection of uranyl(II) ions. The optimized electrodes based on triphenylphosphine sulfide (L¹) and triisobutylphosphine sulfide (L²) responded linearly towards uranyl(II) ions within the range of 1.0 × 10^-7 – 1.0 × 10^-1 M. Good sensitivity (29.32 ± 0.53 and 27.99 ± 0.61 mV per decade) and detection capability up to 7.9 × 10^-8 and 1.0 × 10^-7 M uranyl(II) were observed for L¹- and L²-based electrodes, respectively. The effect of solution temperature on uranyl(II) determination was studied within 10–60 °C. Selectivity studies showed that the electrodes are capable to discriminate uranyl(II) ions over a large number of possible co-existing inorganic interferents. Moreover, they exhibited speedy response, thermal and long-term stability, and significant reusability. Petroleum water samples spiked with uranyl(II) ions were analyzed utilizing the developed electrodes where good recovery and accuracy were achieved, demonstrating the real-life applicability of the developed electrodes.