On-line emulsion formation and multi-element analysis of edible oils by inductively coupled plasma atomic emission spectrometry

A novel simple on-line emulsion formation system for multi-element analysis by inductively coupled plasma atomic emission spectrometry (ICP-AES) was developed. A laboratory made magnetic-stirring micro-chamber was used for continuous edible emulsification with Triton X-100 and for subsequent introduction of the emulsion into ICP-AES. The optimum concentration of oil in emulsion for maximum sensitivity was 50% (v/v). The performance of the system was demonstrated for Ag, Al, B, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, In, Mg, Mn, Ni, Pb, Tl and Zn determination in olive, sunflower and corn oil. Good agreement was found between calibration curves for oil emulsion and aqueous ones for the most of the investigated spectral lines. The calibration curves for each element were linear at least up to 1.0 mg l−1 and the correlation coefficients were ranged between 0.991 and 0.999. The proposed method was applied to the analysis of olive oil sample and compared with ETAAS-wet digestion method. No significant differences were observed between the two methods.