Evaluation of candidate reference material obtained from selenium-enriched sprouts for the purpose of selenium speciation analysis

• Sprouts are capable of converting selenium into organic compounds.
• Selenium enriched sprouts are stable and homogeneous.
• Broccoli and white cabbage sprouts were chosen as candidates reference material.

Selenium is an essential element in animals and humans. Diet supplementation with selenium-rich vegetables has better chemoprotective effect than Se (IV) and SeMet. The production of selenium-enriched vegetables requires a preliminary stage in soil preparation, which may subsequently pose a risk of soil contamination. It seems that the sprouting of seeds under controlled conditions would be a good solution for delivering SeMetSeCys to the human organism. The certified reference material is necessary in order to follow the safety rules during the application of selenium-enriched foods in cancer prevention. Such reference material will contribute to the development of research methods for determining specific species of selenium. Therefore, we undertook an effort to produce the appropriate reference material for Se speciation analysis by using Se-enriched sprouts. Six types of sprouts, mainly from the family Brassicaceae, were selected for the study. The sprouts grown in both media accumulate significant amounts of selenium. However, only the plants cultivated in the medium containing Na2SeO3 are capable of converting inorganic selenium into SeMetSeCys and SeMet. The sprouts of broccoli and white mustard grown in the medium containing 10 mg/L Na2SeO3 were selected as potential candidates for certified reference materials.