Aerosol Dilution Technique for Direct Determination of Ultra-Trace Levels of Cr, Mn, Fe, Co, Ni, Cu, and Zn in Edible Salt Samples by Collision/Reaction Cell Inductively Coupled Plasma Mass Spectrometry (CRC-ICP-MS)

An inductively coupled plasma mass spectrometry method was established for direct determination of some (ultra)trace elements in salt samples applying aerosol dilution approach. As the method does not require any sample pretreatment, contamination risk was very low, and analytical features were excellent. The method detection limits were 12, 6, 18, 2, 34, 68, and 87 ng/l for Cr, Mn, Fe, Co, Ni, Cu, and Zn, respectively. The combinatorial use of collision/reaction cell, and kinetic energy discrimination was found to be very effective to eliminate polyatomic interferences. The accuracy of the method was validated by the analysis of certified reference materials, CWW-TMG waste water and SEM-2011 water sample in high-salt matrix, 0.5 % (w/v) NaCl solution. The relative standard deviations were lower than 11 % for all elements without any sample pretreatment. The spike recovery values were 96-101 % at 0.2 and 1.0 mu g/l, showing the applicability of the presented method for direct (ultra)trace analysis of edible salt samples.