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The total selenium content of selenium-enriched agricultural products was determined by inductively coupled plasma mass spectrometry after microwave digestion. The total selenium content in the tested samples ranged from 27.9 μg/kg to 13.6 mg/kg. High performance liquid chromatography–inductively coupled plasma mass spectrometry was employed to determine selenite and selenate in selenium-enriched rice, tea, and garlic. The separation of inorganic and organic selenium was realized within 15 min by using 40 mmol/L diammonium phosphate (pH 5.0) and 60 mmol/L diammonium phosphate (pH 6.0) as the mobile phase with gradient elution. Selenite and selenate were isolated by ultrasonic assisted extraction at 78 °C for 30 min with 0.1 mol/L potassium hydroxide as the extraction solution. The detection limits were 2.5 and 5 μg/kg for selenite and selenate, respectively. The relative standard deviation was less than 5.5%. Recoveries of inorganic selenium were between 88.2% and 113.0%. The proposed method was successfully applied for the determination of inorganic selenium as well as total selenium in selenium-enriched rice, tea, and garlic. The results showed that inorganic selenium in natural selenium-enriched agricultural products is primarily present in selenite composing no more than 20% of total selenium. [ABSTRACT FROM AUTHOR]

Selenium, as an essential trace element, exerts health effects that are contingent not only on the quantity consumed but also on the specific selenium species present in the dietary. The aim of this study was to investigate the effects of different selenium supplements on the distribution of selenium content, the forms of selenium, and its in vitro bioaccessibility in piglets. Inductively coupled plasma mass spectrometry and high-performance liquid chromatography (HPLC-ICP/MS) were applied to analyze the selenium content and its speciation in tissues and organs of piglets fed with three selenium supplements, sodium selenite (SS), selenium-enriched Cardamine hirsute (CH), and selenium-enriched yeast (SY). The bioaccessibility experiments on the livers of selenium-enriched piglets were conducted by simulating human gastrointestinal digestion. It was found that the kidney has the highest selenium content among the 12 examined organs. The efficacy of different selenium sources in improving the selenium content in piglets ranked in descending order, is as follows: SY, SS, and CH. The predominant form of selenium in the longissimus dorsi muscle is selenomethionine (SeMet), accompanied by smaller quantities of selenocysteine (SeCys) and methyl selenocysteine (MeSeCys). In contrast, the predominant selenium form in the liver is SeCys, along with SeMet and MeSeCys. Piglets fed with Se-enriched yeast exhibited a significant increase in the content and proportion of SeMet in both the longissimus dorsi muscle and liver. Additionally, different selenium species demonstrated varied G and GI bioaccessilities, with SeMet being the highest and SeCys the lowest. • The predominant selenium forms in porcine liver and longest back muscle were SeCys and SeMet, respectively. • The bioaccessibility of pig livers fed various selenium supplements significantly differed (p < 0.05). • Variations in gastrointestinal and gastric bioaccessibility are observed among different selenium forms. [ABSTRACT FROM AUTHOR]

High concentrations of total arsenic (As) has been found in Agaricus blazei Murrill and Tricholoma matsutake samples. It is important to study the As species in A. blazei and T. matsutake for accurate health risk assessment. Total As was measured by inductively coupled plasma-mass spectrometry (ICP-MS). An analytical method was developed to determine As species in mushroom by using anion exchange and cation exchange chromatography coupled to ICP-MS. Total As contents ranged from 5.25 to 69.5 mg kg 1. Arsenobetaine (AsB), inorganic arsenic (iAs), and monomethylarsenic acid (MMA) were the main form of As in A. blazei samples, which accounted for 42.7–88.8 %, 1.59–26.2 %, and 0.74–1.12 % of the extractable As, respectively. AsB, and dimethylarsenic acid (DMA) were the main form of As in T. matsutake samples, which accounted for 88.9–97.9 %, and 1.79–3.80 % of the extractable As, respectively. Arsenocholine (AsC), trimethylarsine oxide (TMAO), and tetramethylarsonium cation (TMA+) were present as well, but only at trace concentrations. The health risk index estimation results indicated that no particular risk of iAs exposure to consumers existed in T. matsutake. The iAs exposure in A. blazei can poses certain health risks. • A methodology for arsenic speciation was established. • Species arsenic in Agaricus blazei Murrill and Tricholoma matsutake was studied. • Low level of inorganic arsenic in Tricholoma matsutake has no health risk to human. • Inorganic arsenic exposure in Agaricus blazei Murrill can poses certain health risks. [ABSTRACT FROM AUTHOR]