Determination of Total Selenium and Extractability of Selenium in Commercially-Available Dietary Supplements by Inductively Coupled Plasma - Mass Spectrometry (ICP-MS)

Exploring the Link between Oxidative Stress, Selenium Levels, and Obesity in Youth

Obesity is a worldwide increasing concern. Although in adults this is easily estimated with the body mass index, in children, who are constantly growing and whose bodies are changing, the reference points to assess weight status are age and gender, and need corroboration with complementary data, making their quantification highly difficult. The present review explores the interaction spectrum of oxidative stress, selenium status, and obesity in children and adolescents. Any factor related to oxidative stress that triggers obesity and, conversely, obesity that induces oxidative stress are part of a vicious circle, a complex chain of mechanisms that derive from each other and reinforce each other with serious health consequences. Selenium and its compounds exhibit key antioxidant activity and also have a significant role in the nutritional evaluation of obese children. The balance of selenium intake, retention, and metabolism emerges as a vital aspect of health, reflecting the complex interactions between diet, oxidative stress, and obesity. Understanding whether selenium status is a contributor to or a consequence of obesity could inform nutritional interventions and public health strategies aimed at preventing and managing obesity from an early age.

A systematic review and meta-analysis of validated analytical techniques for the determination of total selenium in foods and beverages

The intricate balance between the beneficial and harmful effects of selenium (Se) intake means that its quantification in food needs to be done correctly. Therefore, in this review, we systematized 105 articles to identify the most studied methodologies, analytical techniques, and food matrices. Among the analytical techniques employed, inductively coupled plasma mass spectrometry (ICP-MS) (n = 29) emerged as the most commonly used method. The most prevalent hydrolysis methodology to digest Se in food matrices involved the use of nitric acid combined with ultrasound, which improved both the yield and digestion time. Optimal recovery values were achieved when total Se quantification accounted for the sum of Se(IV) and Se(VI) (94.4-99.4%) and for SeCys (88-96.5%). These findings are relevant for advancing methodological approaches, and their results emphasize the importance of developing alternative, faster, and lower-cost protocols for Se quantification in foods and beverages.

A phosphonium ionic liquid conjugated magnetic graphitic carbon nitride nanocomposite: an effective sample pretreatment tool for selenium separation and determination

We established an innovative and easy-to-use methodology for selenium (Se) extraction and determination from real water samples utilizing a magnetic nanocomposite adsorbent (MNC-SPE) aided by an inductively coupled plasma mass spectrometry (ICP-MS) approach. The MNC-SPE adsorbent was fabricated by hybridizing Fe3O4 nanoparticles on the surface of carbon nitride nanosheets (GCN NSs) that were coated with 1-hexyl-3-methylimidazolium hexafluorophosphate ionic liquid (P-IL). A variety of techniques were used to thoroughly analyze the structural and chemical characteristics of MNC-SPE, and appear to have a great number of diverse active surface functional units (imidazole ring and -NH3+). In order to optimize the key factors affecting the Se extraction, parameters including the adsorbent dosage, contact time, eluent type, eluent volume, eluent time, and reusability of adsorbent were extensively studied. The proposed approach was validated under the optimal reaction conditions, and it showed good linearity between 0.15 and 100 pg μL-1 with a significant R2 value (R2 = 0.9994) toward Se metal. Besides, the Se limit of detection (LOD) and limit of quantification (LOQ) are 0.063 pg μL-1 and 0.147 pg μL-1, respectively. Further, by utilizing tap and river water samples, the applicability of the validated method was tested; the approach showed high Se recovery values in the range of 87.6-115.5% for the spiked real-world samples and the interday and intraday precision (RSD%) values of the approach were 4.8% (n = 6). The MNC-SPE can be regenerated and reused for four consecutive extraction-desorption cycles by employing 0.5 M NaOH eluent.

Selenium in Brazil nuts: An overview of agronomical aspects, recent trends in analytical chemistry, and health outcomes

Se is an essential element in mammals. We review how its bioavailability in soil and the ability of plants to accumulate Se in foods depends on the soil Se profile (including levels and formats), besides to describe how the various selenoproteins have important biochemical functions in the body and directly impact human health. Owing to its favorable characteristics, the scientific community has investigated selenomethionine in most nut matrices. Among nuts, Brazil nuts have been highlighted as one of the richest sources of bioavailable Se. We summarize the most commonly used analytical methods for Se species and total Se determination in nuts. We also discuss the chemical forms of Se metabolized by mammals, human biochemistry and health outcomes from daily dietary intake of Se from Brazil nuts. These findings may facilitate the understanding of the importance of adequate dietary Se intake and enable researchers to define methods to determine Se species.