Cadmium and Lead Determination in Freshwater and Hemodialysis Solutions by Thermospray Flame Furnace Atomic Absorption Spectrometry Following Cloud Point Extraction

• Published in: Journal of the Brazilian Chemical Society Vol. 26; no. 3; pp. 490 - 497
• Main Authors: Garcia, Samara, Gerondi, Fabiana, Paixão, Thiago R. L. C., Arruda, Marco A. Z., Gaubeur, Ivanise
• Format: Journal Article
• Language: English
• Published: Sociedade Brasileira de Química 01.03.2015
• Subjects: CHEMISTRY, MULTIDISCIPLINARY; cloud point extraction; cadmium; TS-FF-AAS; lead; DPKSH
• ISSN: 0103-5053; 1678-4790
• DOI: 10.5935/0103-5053.20150001

Cloud point extraction was employed for the separation and preconcentration of cadmium and lead prior to the determination by thermospray flame atomic absorption spectrometry. Di-2- pyridyl ketone salicyloylhydrazone (DPKSH) was used as complexing agent and the cadmium and lead complexes were extracted from the aqueous phase by the Triton X-114 surfactant. The variables associated with the preconcentration (pH as well as DPKSH, surfactant and electrolyte concentration) were optimized by using a full factorial design with two levels, four variables and a central composite. Under the optimized conditions, a sample volume of 100 µL was introduced into a hot Ti tube at a flow rate of 0.6 mL min-1 and the integrated absorbance was measured. Calibration curves were obtained with linear ranges of 0.075-2.0 µg L−1 (Cd) and 2.5-100 µg L−1 (Pb). The detection limits of 0.04 µg L−1 (Cd) and 1.3 µg L−1 (Pb) (99.7% confidence level) were obtained. The proposed method was applied to hemodialysis solutions and water samples. The accuracy of the method was evaluated by analyzing a certified reference material (NIST CRM 1643e) and the results were in agreement with the certified values at a 95% confidence level according to t-test.