Avances en Química (Sep 2010)
Determinación de níquel en cereales y derivados mediante extracción y preconcentración en línea con detección por EAA
Abstract
Determination of nickel in cereals and derivates by on line extraction and preconcentration with AAS detection. An analytical methodology for the determination of nickel traces in commercial solid samples of cereals and corn flour was developed. Nickel was on-line extracted from solid samples in a lab-made cell incorporated to a flow injection system (FIA). After the extraction, a neutral chelate between nickel and ammonium pyrrolidinedithiocarbamate (APDC) was adsorbed on a minicolumn packed with zeolite type YNa. Finally, the chelate was eluted with methyl isobutyl ketone (MIBK) for nickel detection in a flame atomic absorption spectrometer. Under the optical conditions a preconcentration factor of 85 was readily achieved related to the direct introduction of aqueous solutions into an atomic absorption spectrometer. The detection limit (3σ), RSD% and linear calibration graphs were 0.72, 0.22 and (30-70) μg.l-1, respectively, for a sample volume of 6 ml.
