Uranyl ion-selective optical test strip

A novel, optical sensor, test strip has been developed for the spectrophotometric determination of trace amounts of uranyl ions, UO22+, based on immobilization of C.I. Mordant Blue 29 (Chromazurol S)/cetyl N,N,N-trimethyl ammonium bromide ion pair on a triacetyl cellulose membrane. Optimization of the sensor for the detection of low levels of uranyl ion is described. The test strip responded linearly to uranyl ions between 3.0 × 10−7 and 6.0 × 10−5 mol L−1; the reproducibility of the sensor at a medium level of UO22+ activity was ±0.55%. The optical sensor can be regenerated using 0.01 mol L−1 HCl or 0.01 mol L−1 NaF solution after 10 min. The developed test strip was used in the determination of UO22+ in ground water samples.