The European Commission Regulation No 2023/915 and amendments sets maximum limits for certain elements in salts, including arsenic (0.5 mg/kg), mercury (0.1 mg/kg), cadmium (0.5 mg/kg), and lead (1 mg/kg for salt or 2 mg/kg for unrefined salt). Therefore, it is critical to develop precise analytical methods to determine the elemental compositions of various salt samples, which is challenging due to the high concentrations of sodium.

This work employs inductively coupled plasma-optical emission spectroscopy (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS/MS) to analyze various elements in a panel of 15 salts purchased in Danish supermarkets, with a large variety of origins (Atlantic, Mediterranean, Himalayas, etc.) and extraction methods (from soils or seas), as well as different crystal sizes. During this study, 17 elements were quantified in these samples, including those which are regulated. The list of elements analyzed is as follows: Al, As, Ca, Cd, Cr, Cu, Fe, Hg, K, Mg, Na, Ni, P, Pb, S, Se and Zn. Preliminary data suggests that the regulated elements (Pb, Hg, As, Cd) can be detected in varying concentrations within the samples chosen for this study. 

The analysis of elements such as Hg by ICP-OES or ICP-MS/MS have been implicated with poor detection limits, high carryover effects and sample instability. We present a method of sample preparation for ICP-OES-Hg analysis in refined and gourmet salt samples, which minimizes these effects. Regarding the comparison between ICP-OES and ICP-MS/MS, the results showed that both instruments could be used. However, it seems that ICP-MS/MS is more sensitive for the detection of trace elements.