Abstract

microextraction technique for the pre-concentration of cadmium ions. The extraction agent was immobilized on small pieces of porous polypropylene flat membrane as a supported liquid membrane. The analyte extraction was performed by immersing the modified film in the sample solution, and via a complex formation between the immobilized dithizone on the film and cadmium ions. After the thin-film microextraction process, the colored cadmium-dithizone complex was directly measured by a smartphone colorimetric analysis. Under optimized conditions, the linear dynamic range, the limit of detection, and the limit of quantification were 0.5–300.0, 0.1, and 0.4 μg L–1 , respectively. The developed technique was successfully employed to quantify cadmium ions in water and food samples. The high relative recovery values (95.0–103.0%) along with relative standard deviations of less than 2.5% were obtained for the spiked samples.