A green, novel and simple microprecipitation technique for separation and preconcentration of cadmium with 1-(2-thiazolylazo)-2-naphthol in food samples and determination by microsampling flame atomic absorption spectrometry

Abstract

A microprecipitation is developed by using Cd(II)–1-(2-thiazolylazo)-2-naphthol (TAN) microprecipitate for the preconcentration of cadmium at trace levels. This condition facilitates phase separation, and the aqueous phase can be removed with a syringe, while the remaining solid particles are dissolved in concentrated nitric acid and introduced into a flame atomic absorption spectrometer using a microinjection system for Cd(II) determination. Quantitative recovery values for cadmium were obtained at pH 8. The method offered a limit of detection (LOD) of 0.25 μg L⁻¹, a limit of quantification (LOQ) of 0.83 μg L⁻¹ and a relative standard deviation (RSD) of 5.5%. The procedure was validated by addition/recovery tests and by applying bovine liver certified reference materials. The method was successfully applied to the preconcentration and determination of cadmium in food samples.