A b s t r a c t

This study presents a new procedure for preconcentration and determination of trace level of copper (II) in water samples. The method is based on the adsorptive enrichment of copper (II) complex with N-[(S)-3-mercapto-2-methylpropionyl-Lproline chelate on naphthalene column. After the preconcentration stage, the analyte was eluted with a HNO₃ solution and determined by flame atomic absorption spectrometry (FAAS). The effect of different variables such as pH, sample volume, amount of chelate, flow rate and eluent solution on the recovery of the analyte was investigated. The effect of some matrix elements, such as Fe, Ni, Na, K, Ca, and Mg, on recovery of copper has also been studied. The calibration graph was linear in the range 25 – 120 μg l^-1 of copper in the initial solution with r = 0.9994. The limit of detection based on 3S_b criterion was 5μg l^-1 and the relative standard deviation for ten replicate measurements of 50 and 90 μg l^-1 of copper was 1.7 and 2.1 %, respectively. The accuracy of the method confirmed by analyzing of copper in certified sample material (NBS-Ounce metal 124d). The results demonstrated a good agreement with the certified value. The method was successfully applied for determination of copper in tap and wastewater samples.

H. Zavvar Mousavi and H. Shirkhanloo