An efficient procedure for preconcentration of cadmium using modified sawdust as an adsorbent

Department of Chemistry, Khouzestan Science and Research Branch, Islamic Azad University, Ahvaz, Iran E-mail : Sh.elhami@khouzestan.Srbiau.ac.ir Manuscript received online 03 July 2014, revised 07 August 2014, accepted 24 August 2014 A procedure for the separation and preconcentration of trace amounts of cadmium is proposed. It is based on the adsorption of CdCl3 – ions solution onto a column of sawdust modified with diethylenetriamine. Cadmium complex is quantitatively retained on the column in the pH range 3–5.5. The cadmium complex was eluted with 2 mL of nitric acid and cadmium was measured by flame atomic absorption spectrometry. Ten replicate determinations of 5 and 25 ng mL–1 of cadmium gave a relative standard deviation of 2.42 and 1.19%, respectively. The limit of detection based on 3Sb was 0.20 ng mL–1. The interference of large number of anions and cations was studied. The procedure was applied to the determination of cadmium in several natural water samples. The standard addition technique was applied and the obtained recoveries revealed that the proposed procedure has a good accuracy. A high preconcentration factor (250), simplicity and high regeneration of adsorbent were the main advantages in this analytical method