Advances in electrospray mass spectrometry for the selenium speciation: Focus on Se-rich yeast

Selenium is an essential element of which the deficiency is often compensated for by supplementation with products based on yeast grown on Se-rich media. Advances in HPLC with element- and molecule-specific detection by mass spectrometry have resulted in evidence of the presence of hundreds of selenocompounds in Se-rich yeast, with different properties and in a large concentration range. This spurs interest in extending -omics-type approaches to selenium speciation analysis to other samples with the ultimate goal to confer biological significance to the obtained data. This review critically evaluates the recent advances in selenium speciation analysis, especially in terms of sensitivity and specificity of ICP-MS and electrospray-MS, and, in terms of resolution, mass accuracy and multistage fragmentation by electrospray-MS. A focus is made on the evolution of the perception of the competitiveness and complementarity of ICP-MS and electrospray-MS detection in HPLC for qualitative and quantitative Se speciation analysis.