Selective separation and determination of palladium ions using isatin-3-(4-phenyl-3-thiosemicarbazone) as a chelating agent via flotation methods from different water samples

Many research studies have been applied for the separation and determination of palladium from different samples via precipitation, ion exchange, and solvent extraction methods. In this study, an easy and non-time-consuming ion flotation technique was investigated to separate this metal ion prior to determination using inductivity-coupled plasma optical emission spectrometry (ICP-OES). Isatin-3-(4-phenyl-3-thiosemicarbazone) (IPTS) was prepared and characterized to be used as an active color-forming chelating reagent. Experimental results showed that a soluble colored (1:1) complex was formed between IPTS and Pd(II), which could be separated successfully by the ion flotation technique using a surfactant-controlled methodology. Separation efficiency of Pd(II) reached its optimum value of 100% at pH 3.0 using 3.8 × 10−6 IPTS and methyl isobutyl ketone (MIBK) as the collector. The various parameters, like concentration of IPTS, pH, surfactant, ion interference, sample volume, and temperature, that affect the flotation efficiency, were optimized. The analytical detection limit was 0.6125 µg mL−1 for Pd (II). The recoveries of Pd (II) found in water samples and synthetic mixtures are over 97%, and the relative standard deviation (RSD) was 1.12%. Furthermore, changing the pH conditions of the aqueous phase facilitated the selective extraction of Pd (II) from a range of complex matrices. The current study demonstrated that at pH 3, Pd(II) is completely separated in the micellar phase while the rest ions remain in the aqueous phase. These results proved the ability to selectively separate Pd(II) from real samples, water samples, and synthetic mixtures.