Detection and characterization of biogenic selenium nanoparticles in selenium-rich yeast by single particle ICPMSElectronic supplementary information (ESI) available: Information about isotopic abundance and spectral interference for Se isotopes, time scans of ultrapure water, size distributions of SeNP suspensions, signal distributions of samples, TEM image and EDS spectrum. See DOI: 10.1039/c7ja00378a

• Main Authors: Jiménez-Lamana, Javier, Abad-Álvaro, Isabel, Bierla, Katarzyna, Laborda, Francisco, Szpunar, Joanna, Lobinski, Ryszard
• Format: Article
• Language: English
• ISSN: 0267-9477; 1364-5544
• DOI: 10.1039/c7ja00378a

A method based on single particle inductively coupled plasma mass spectrometry (SP-ICPMS) was developed for the analysis of commercial Se-rich yeasts, to confirm the occurrence of selenium nanoparticles in these food supplements. A considerable reduction of background levels was achieved by combining data acquisition at microsecond dwell times and the use of a H 2 reaction cell, improving by a factor of 10 the current state-of-the-art methodology, and bringing size detection limits down to 18 nm for selenium nanoparticles. The presence of nanoparticulate selenium was revealed by size-exclusion chromatography ICPMS, with detection of a selenium peak at the exclusion volume of the column showing absorption at a wavelength corresponding to selenium nanoparticles. SP-ICPMS allowed us to confirm the presence of Se-nanoparticles, as well as to calculate the nanoparticle size distribution, from information about the shape and elemental composition of the nanoparticles obtained by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS), respectively. These results reveal the significance of nanoparticles in the speciation of metals and metalloids in biological samples and the capability of SP-ICPMS in combination with TEM-EDS to carry out these analyses. The occurrence of SeNPs in commercial Se-rich yeasts was confirmed by SP-ICPMS for the first time.