Es 54.32 mg g-1 ) [47]. The new strategy developed right here permitted for the simultaneous determination arsenic and selenium forms. Inorganic selenium species have been found in most of the samples, but the predominant determined form was Se(VI), specifically for seafood, and the main organic type was Se-methionine, which was discovered in each onions and seafood samples. The highest content material of this form was discovered in white sweet onion. The FAUC 365 custom synthesis Semethylselenocysteine forms, while in the hot water extract from onion bulbs, similar to the findings within this study, Se-methionine and additional Se-methylselenocysteine were also observed [48]. Additional research on selenium speciation in enriched-by-Se(IV) onion samples was conducted by [49]. It needs to be underlined that they performed only qualitative speciation analysis and obtained for HCl extract Se-methylselenocysteine and Se-methionine forms, while for enzymatic extract, inorganic selenium, Se-cystine, and Se-methionine (the highest signal) types [49]. In addition, SeMet was the dominant kind in enzymatic extracts of plant meals like: buckwheat, green pea, strawberries, rice, cabbage, and kale, which were therapy by Se(IV) [50]. These outcomes are in accordance with the present speciation data for onion samples and may be a confirmation from the statement that SeMet form has been located to become far more bioavailable and significantly less toxic than inorganic selenium species [51]. Additionally, the sum concentration of species of selenium in onion samples was greater when compared with seafood data. It might be suggested that this difference may have been caused by the fertilization method employed for cultivation as a result of deficiency of selenium inside the soil. Kapolna and Fodor (2007) estimated that, when onions are enriched with Se species, the total selenium content increases substantially, in particular inside the bulbs, which may perhaps result in higher Se contents in green onion samples [52]. It can be well-known that selenium is definitely an crucial micronutrient for humans, and seafood is one of the key selenium sources [40]. Additionally, its toxicity and bioavailability strongly is determined by its chemical type and concentration [50]. In seafood water extracts in the present study, in contrast to data for onion samples, the Se(VI) was the predominant kind. Even so, greater concentration was marked for Se-cystine and SeMet forms. In seafood samples, the Se(IV) was marked only in white blanched shrimp. Jagtap et al. (2016) determined the SeMet was discovered in fish muscle and liver tissues soon after enzymatic hydrolysis in the range 1.0.4 mg g-1 , which can be significantly higher in comparison to this study [53]. Reduce concentration (from 0.12.0 mg g-1 ) of SeMet was obtained by Sele et al. (2018), who confirmed that SeMet was the key Se species in muscle of Atlantic salmon fed both basal diets and diets supplemented with selenised yeast [54]. These findings are in agreement together with the earlier statement that SeMet is a lot more readily out there than inorganic Se species [54], which is often explained by greater data for SeMet when compared with Se(VI) within the present study. Taking into account the sum of all forms of selenium in water extracts, the marked variety 0.13.47 mg g-1 was in the identical.