Determination of cadmium(II) ion by atomic absorption spectrometry after cloud point extraction

In this work, cloud point extraction (CPE) technique was developed for the separation and pre-concentration of Cd(II). CPE was used with lipophilic hexadentate (N4O2) Schiff base ligand, L-22pysa (1, C24H26N4O2). The methodology is based upon the formation of a Cd(II)/L complex soluble in a micellar phase the non-ionic surfactant Triton X-114. This complex is then extracted into the surfactant-rich phase above its cloud point temperature. Several important variables that affect the CPE were investigated and optimized. Under the optimum experimental conditions, the calibration graph was linear over the range 1-100 ng mL(-1) with a correlation coefficient of 0.9997. The detection limit obtained under optimum conditions was 0.44 ng mL(-l). The proposed method was successfully applied to the determination of Cd(II) in rice and various water samples.