Search Results (7)

This study aims to investigate the effects of selenium (Se) fortification on growth performance and the Se content in kale using Se fertilizer, and it determines the influences of Se fortification on the metabolic profile of kale using quasi-targeted metabolomics. The results showed that Se fortification increased the plant height and leaf weight of kale, up-regulated the total Se content and decreased the chlorophyll and total phenolic contents in kale leaf. Se fortification elevated selenate (Se(IV)), selenite (Se(VI)), selenocystine (SeCys₂), Se-methylselenocysteine (Se-MeSeCys) and selenomethionine (SeMet) contents, as well as total contents of Se in different forms in kale leaf. Se fortification also changed the metabolic profile of kale leaf, via six particular types of compounds (amino acid and its derivatives; organic acid and its derivatives; carbohydrates and its derivatives; lipids; flavonoids; organoheterocyclic compounds) and eight metabolic pathways (alanine, aspartate and glutamate metabolism; amino sugar and nucleotide sugar metabolism; sulfur metabolism; starch and sucrose metabolism; taurine and hypotaurine metabolism; glycolysis/gluconeogenesis; fructose and mannose metabolism; nitrogen metabolism). Moreover, 24 metabolic biomarkers were screened for kale leaf affected by Se fortification. Furthermore, correlations were observed between metabolic biomarkers and Se contents as well as speciation. These results indicate that Se fortification has a significant influence on the growth performance and nutritional compounds of kale, providing references for the future study on the production and bioactivity of Se-enriched kale. Full article

The contamination of drinking water sources with selenium (Se) oxyanions, including selenite (Se(IV)) and selenate (Se(VI)), contains serious health hazards with an oral intake exceeding 400 µg/day and therefore requires urgent attention. Various natural and anthropogenic sources are responsible for high Se concentrations in aquatic environments. In addition, the chemical behavior and speciation of selenium can vary noticeably depending on the origin of the source water. The Se(VI) oxyanion is more soluble and therefore more abundant in surface water. Se levels in contaminated waters often exceed 50 µg/L and may reach several hundred µg/L, well above drinking water limits set by the World Health Organization (40 µg/L) and Germany (10 µg/L), as well as typical industrial discharge limits (5–10 µg/L). Overall, Se is difficult to remove using conventionally available physical, chemical, and biological treatment technologies. The recent literature has therefore highlighted promising advancements in Se removal using emerging technologies. These include advanced physical separation methods such as membrane-based treatment systems and engineered nanomaterials for selective Se decontamination. Additionally, other integrated approaches incorporating photocatalysis coupled adsorption processes, and bio-electrochemical systems have also demonstrated high efficiency in redox transformation and capturing of Se from contaminated water bodies. These innovative strategies may offer enhanced selectivity, removal, and recovery potential for Se-containing species. Here, a current review outlines the sources, distribution, and chemical behavior of Se in natural waters, along with its toxicity and associated health risks. It also provides a broad and multi-perspective assessment of conventional as well as emerging physical, chemical, and biological approaches for Se removal and/or recovery with further prospects for integrated and sustainable strategies. Full article

Herein, a method was established for the speciation of six selenium species by high performance liquid chromatography-inductively coupled plasma-tandem mass spectrometry (HPLC-ICP-MS/MS). The factors affecting separation were carefully investigated, including ionic strength, pH, and methanol content. Six species of selenium could be completely separated within 20 min, under the mobile phase of 25 mM citric acid in pH = 4.0 containing 2% methanol. The detection limits of selenite (Se(IV)), selenate (Se(VI)), selenomethionine (SeMet), selenocystine (SeCys₂), methylselenocysteine (MeSeCys), and selenoethionine (SeEt) were 0.04, 0.02, 0.05, 0.02, 0.03, and 0.15 ng mL⁻¹, respectively. To verify the practicality of this method, the analysis of selenium-enriched foods such as selenium-enriched spring water, selenium-enriched salts, and selenium-enriched tea were conducted, and recovery of 93.7–105% was achieved with RSD < 5%, revealing the high practical utility of the proposed method. Full article

This paper presents a new method for the simultaneous speciation analysis of arsenic (As(III)-arsenite, As(V)-arsenate, DMA-dimethylarsinic acid, MMA-methylarsonic acid, and AsB-arsenobetaine) and selenium (Se(IV)-selenite, Se(VI)-selenate, Se-Methionine, and Se-Cystine), which was applied to a variety of seafood and onion samples. The determination of the forms of arsenic and selenium was undertaken using the High-Performance Liquid Chromatography Inductively Coupled Plasma Mass Spectrometry (HPLC–ICP–MS) analytical technique. The separation of both organic and inorganic forms of arsenic and selenium was performed using two analytical columns: an anion exchange column, Dionex IonPac AS22, containing an alkanol quaternary ammonium ion, and a double bed cation–anion exchange guard column, Dionex Ion Pac CG5A, containing, as a first layer, fully sulfonated latex for cation exchange and a fully aminated layer for anion exchange as the second layer. The ammonium nitrate, at pH = 9.0, was used as a mobile phase. The method presented here allowed us to separate the As and Se species within 10 min with a suitable resolution. The applicability was presented with different sample matrix types: seafood and onion. Full article

The research on selenium presence in water resources has revealed the need to determine the respective aquatic species. As selenium oxyanions SeO₃²⁻ (Se^IV) and SeO₄²⁻ (Se^VI) predominate in natural waters, their determination is essential, mainly due to different ecotoxicity properties, as well as to different removal options from relevant-polluted waters. This study focuses on the SeO₃²⁻/SeO₄²⁻ speciation/separation and determination through the selective adsorption of SeO₃²⁻ only onto specific iron oxy-hydroxides (FeOOHs). For this purpose, the laboratory prepared FeOOHs examined along with the commercially available relevant material (Bayoxide), which was found to present optimum results for the speciation of selenium oxyanions, at the low concentration range 10–100 μg/L, using a dose of 0.5 g/L of adsorbent and gently stirring for 30 min at the usually encountered pH value of 7.3 ± 0.2. Moreover, the relevant experiments showed that the other major ions Cl⁻, HCO₃⁻, NO₃⁻, SO₄²⁻, Ca²⁺, Mg²⁺, Na⁺, possibly found in most natural waters at the concentration range 0–200 mg/L, as well as silicon, total organic carbon (TOC) of natural organic matter (NOM) and iron at the concentration range 0–50 mg/L, 0–5 mg/L and 0–1 mg/L, respectively, did not interfere with the selective adsorption of Se(IV). Furthermore, the most important advantage of this selective speciation method is its implementation/combination with all commonly applied analytical methods for the determination of total selenium. Full article

Identification and quantification of the selenium species in biological tissues is imperative, considering the need to properly understand its metabolism and its importance in various field of sciences, especially nutrition science. Although a number of studies deals with the speciation of selenium, speciation analysis is still far from being a routine task, and so far strongly depends on the type of the samples. We present a study aimed to examine speciation analysis of Se in tissues of livers, muscles, and hearts obtained from lambs, namely in liver, muscle, and heart. The studied lambs were fed with the diet enriched with an inorganic (as sodium selenate) and organic chemical form of Se (as Se-enriched yeast) compounds with simultaneous addition of fish oil (FO) and carnosic acid (CA). The first part of the work was focused on the optimization of the extraction procedure of selenium compounds from tissues. Next, hyphenated high performance liquid chromatography and inductively coupled plasma mass spectrometry (HPLC–ICP–MS) was used for the identification of five seleno-compounds—Se-methionine (SeMet), Se-cystine (SeCys2), Se-methyl-Se-cysteine (SeMetSeCys), and Se(IV) and Se(VI). Verification of the identified seleno-compounds was achieved using triple-quadrupole mass spectrometer coupled to high performance liquid chromatography (HPLC–ESI–MS/MS). The applied procedure allowed for quantitative analysis of SeMet, SeCys2, and SeMetSeCys, in biological tissues. The developed analytical protocol is feasible for speciation analysis of small molecular seleno-compounds in animals samples. Full article

A new type of cross-linked chitosan was synthesized with Diethylene Triamine (DCCTS). The adsorption of Se (VI) on DCCTS was studied. The effect factors on adsorption and the adsorption mechanism were considered. The results indicated that the DCCTS could concentrate and separate Se (IV) at pH = 3.6; the maximum adsorption efficiency was 94%, the adsorption equilibrium time was 30 min; the maximum adsorption capacity was 42.7 mg/g; the adsorption fitted Langmuir equation. A novel method for speciation of Se (VI) and Se (IV) in environmental water samples has been developed using DCCTS as adsorbent and ICP–OES as determination means. The detection limit of this method was 12 ng/L, the relatively standard deviation was 4.5% and the recovery was 99%~104%. Full article