FAAS Determination of Trace Amount of Cadmium with Functional Temperature-Control-Ionic Liquid Extraction

FAAS was applied to the determination of trace amount of cadmium with functional temperature-control-ionic liquid extraction. The optimized conditions found were as follows: ① amount of ionic liquid: 0.25 g; ② pH of the solution: 5.81; ③ time of centrifugation: 30 min; ④ amount of 2 mol·L-1 hydrochloric acid solution (back-extractant): 5. 00 mL; ⑤ time of ultrasonic extraction: 30 min; ⑥ times of back-extraction: 3. Linear relationship between values of absorbance and mass concentration of cadmium was obtained in the range within 1.20 mg·L-1,with detection limit (3s/k) of 0.027 mg·L-1. The proposed method was applied to the analysis of simulated water sample,giving results in consistency with the known value. Values of recovery found by standard addition method were in the range of 102%-110%,and values of RSD′s (n=3) less than 1.0%.