Determination of cadmium, lead, and copper in margarines and butters by galvanostatic stripping chronopotentiometry.

A galvanostatic stripping chronopotentiometric (GSCP) method for the simultaneous determination of cadmium, lead, and copper in commercial margarines and butters is described. Quantitative analyses of heavy metals in the mineralized fat samples, except standard addition method, were carried out automatically. The mean concentrations of Cd(II), Pb(II), and Cu(II) in different types of margarines and butters varied from 9.1 to 26.2, 9.2-14.2, 298.2-364.0 microg x kg(-)(1), respectively, that is below the legal requirements. The detection limits are 0.02, 0.02, and 0.06 microg x L(-)(1) for Cd(II), Pb(II) and Cu(II), while the reproducibilities are 3.3, 5.7, and 2.0%, respectively. The comparable precision (RSD = 0.76-4.5 and 0.87-4.9%) and recovery (96.7-102.2% and 96.1-103.2%) for the proposed GSCP and standard GFAAS methods, demonstrate the benefit of GSCP method in the routine analysis of heavy metal ions in fats.