Abstrato

Determination and preconcentration of nickel in some geological, environmental and biological samples by FAAS

Harun Ciftci, Esen Ciftci

In this study, new, sensitive, simple and validated solid-phase extraction method is developed for the determination of nickel. Nickel was preconcentrated as 4-(2-Pyridylazo) resorcinol chelates (Ni-PAR) fromsample solutions using a column containing Duolite XAD-761 and determined by flame atomic absorption spectrometry (FAAS). The optimal experimental parameters for the nickel assay have been investigated. The optimum pH value for quantitative sorption of Ni-PAR was found between 3.5 and 4.5. Elution process was performed by 5 mL of 2 mol L-1 HCl. The sorption capacity of resinwas determined to be 1.8mg g –1 forNi. The preconcentration factor was 120. In optimized conditions, the detection limit for nickel was found to be 0.64 ìg L-1. The method was applied to different waters, food and guinea pig tissue samples. Calculated recoveries for waters, bean and guinea pig lung samples were as 98.6-102.1, 98.3 and 98.9 % respectively. The method was extended for determination of nickel in standard reference materials (NIST 1573 a-tomato leaves) and to investigate the accuracy of the proposed procedure. Influences of some interfering species were also investigated.