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Currently, planting selenium-rich crops using inorganic selenium such as selenate and selenite is used to address human selenium deficiency problems. In this paper, besides the above two traditional inorganic selenium speciation, we chose a new organic selenium speciation of potassium selenocyanoacetate to investigate the different effects of selenium speciation on selenium absorption, selenium transformation and cadmium antagonism via foliar application. Plantingexperiments showed that the selenium content of garlic bulbs treated with organic selenium was 1.8-3.9 times higher than that of inorganic selenium. Additionally, the absorption and transformation efficiency of organic selenium in garlic was also the highest, reaching over 95 %. Importantly, it was noteworthy that the cadmium content in bulbs treated with organic selenium was significantly lower than the Chinese food safety standard (0.2 mg/kg). Hence, this study provides an efficient organic selenium speciation which is beneficial to meet human selenium requirements and ensure safe utilization of cadmium-contaminated soils., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Accurately quantifying selenium (Se) speciation and transformation in Se-enriched crops is highly significant for human health. The investigation of Se species in Se-enriched crops involves assessing the enrichment of both organic and inorganic Se species, considering their plant families and edible parts. The staple crops of rice, corn, and wheat showed no or less inorganic Se with the increase of total Se; however, potatoes expressed a proportion of selenate [Se(VI)]. In addition, the organic Se proportions in Se-enriched crops of Cruciferous, Brassicaceae , and Umbelliferae plant families were relatively lower than the proportion of inorganic Se. Concurrently, the edible parts of the Se-enriched gramineous or cereal crops enriched with organic Se and crops with fruit, stem, leaf, and root as edible parts contain the maximum percentage of organic Se with a certain proportion of inorganic Se. This study contributes to a sparse body of literature by meticulously discerning appropriate Se-enriched crop selection through a comprehensive evaluation of Se speciation and its organic and inorganic accumulation potential.

Seleno-Yeasts (SY) used as feed additives are known to contain different Selenium (Se) species. Seleno-Yeasts has been shown, on previous analytical methods, to contain selenomethionine (SeMet), selenocysteine (SeCys), selenate (Se IV ) and selenite (Se VI ), and various other organic and inorganic Se forms identified but rarely quantified. A new advanced method has allowed elemental Se (Se 0 ), an inorganic Se species, to be quantified, thereby obtaining better insight into the proportion of inorganic Se in SY products. The study aimed to quantify the Se 0 in SY products and assess the proportion of inorganic Se in SY. The Se speciation of 13 fresh commercials SY from different suppliers and batches, was assayed for the total Se, inorganic Se species (Se IV , Se VI and Se 0 ), and organic Se species (SeMet and SeCys). Results on total Se were in line with the expected Se concentrations for all evaluated samples. The proportion of Se present as Se 0 ranged from 3.6% to 51.8%. The quantity of Se 0 in the SY products, added to Se IV and Se VI , indicated an average proportion of inorganic Se of 14.2% for the 13 analyzed SY products. The proportion of Se as SeMet ranged from 19.0% to 71.8%, (average of 55.8%), and a large variability in the SeMet content was observed. The SeCys content was also variable, with an average of 3.8%, relative to the total Se. In conclusion, advances in the analytical characterization have revealed that SY products can have a significantly high proportion of inorganic Se, which could affect the bioavailability of Se from SY supplements and explain their variable and lower bio-efficacy than pure SeMet supplements, such as hydroxy-selenomethionine., (© 2023. The Author(s).)

Speciation of selenium (Se) is typically carried out using a sophisticated technique such as ICP-MS after preconcentration using an adsorbent; however, the separation and preconcentration of inorganic Se has not been realized in the solutions containing high concentrations of SO 4 2- . A dithiocarbamate-modified cellulose (DMC) was used in this study for the selective extraction and preconcentration of inorganic Se in wastewater, with a portable liquid electrode plasma-optical emission spectrometry (LEP-OES) being employed for quantification. DMC was found to selectively and quantitatively adsorb selenite (Se IV ) over a wide range of pH (1.0-8.0); however, less than 3.0% of selenate (Se VI ) was adsorbed in a pH range of 3.0-11. Quantitative extraction of Se IV was achieved even in the presence of 3.5 mol L -1 SO 4 2- . The maximum sample volume from which 10 mg of DMC could quantitatively extract Se IV was found to be 500 mL. KOH (0.60 mL, 1.5 mol L -1 ) was found to quantitatively desorb Se IV retained on the adsorbent and yielded an enrichment factor of 833. The recovery of Se species from synthetic flue-gas desulfurization wastewater containing Se IV and Se VI at concentrations of 5.0 µmol L -1 was 96.2 ± 1.8% and 105.8 ± 1.8%, respectively., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Cadmium (Cd) is an element injurious for human health and is possibly toxic to organisms at minor concentrations. While some of other trace metallic elements have antagonistic features to it. One of them is the interaction between selenium (Se) and Cd in plant different organs. Literature review disclosed that the intake of Se to some extent can reduce the accumulation of Cd in plants, while the research on of trace metallic elements (Cd) and Se-enriched food (rice) in the living body has rarely been reported. This study intended to explore whether there was a mitigating effect of Se-enriched rice on mice poisoned with Cd. A mouse model of low-dose and high-dose Cd poisoning was established (supplemented with cadmium chloride(CdCl 2 ·2½H 2 0)), followed by feeding two groups (1) Se-enriched rice and (2) setting an equal amount of inorganic Se group. After that, the impact of Se-enriched rice on the antioxidant activity was evaluated. The Se-enriched diet enhanced the total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and enzyme activities of GSH peroxidase (GSH-Px) in mice livers and kidney whereas significantly decreased the malondialdehyde (MDA) contents. Moreover, the degree of physiological damage in mice with low cadmium poisoning was significantly alleviated, and the expression of antioxidant genes (Nrf-2, GPX1, TrxR2, TNF-2) was increased. In conclusion, the Se-enriched diet has a positive effect on the biological effects in mice, and it can be used as a daily diet to resist damage to the body's low Cd state and support enzymatic antioxidant systems by eliminating oxidative injury.

The present study aimed to investigate the influence of maternal selenium supplementation on the skeletal muscle development of the offspring. A total of 720 Ross 308 broiler breeders at 24-week-old were allocated into 3 treatments with 6 replicates of 40 hens each and fed with 0 mg/kg-(group Se/C), 0.5 mg/kg organic-(group Se/O), and 0.5 mg/kg inorganic-(group Se/I) selenium, respectively for 8 weeks. The male offspring from each nutritional treatment were divided and housed into 8 cages of 12 birds each and fed with a commercial diet supplemented with selenium from Na 2 SeO 3 at 0.15 mg/kg. Results showed that Se/O group had the highest selenium deposition (P < 0.05) in the egg yolk and albumen. Furthermore, maternal selenium supplementation promoted breast muscle yield; increased serum insulin and IGF-I concentration; upregulated AKT, mammalian target of rapamycin (mTOR), P70S6K, Myf5, MyoD, MyoG, and SelW mRNA levels; and improved the phosphorylation of AKT at Serine 473 residue, mTOR at Serine 2448 residue, and FOXO at Serine 256 residue in skeletal muscles of the offspring. In contrast, the hens' diet supplemented with selenium could result in reduction of uric acid level in serum and downregulation of Atrogin-1 and MuRF1 mRNA levels in the skeletal muscle of the offspring. Additionally, no significant effect on the skeletal muscle development post-hatch was observed between organic and inorganic selenium supplementation. In conclusion, maternal organic selenium supplementation improved selenium deposition in egg; however, no significant effect has been detected on the breast muscle development of the offspring of broiler breeder compared with inorganic selenium supplementation.

This study aimed to assess the interaction between vitamin B6 and selenium (Se) for the flow of Se towards the Se-dependent glutathione peroxidase (GPX) system in response to oxidative stress naturally induced by oestrus in a pubertal pig model. At first oestrus, forty-five gilts were randomly assigned to the experimental diets (n=9/group): basal diet (CONT); CONT+0.3mg/kg of Na-selenite (MSeB60); MSeB60+10mg/kg of HCl-B6 (MSeB610); CONT+0.3mg/kg of Se-enriched yeast (OSeB60); and OSeB60+10mg/kg of HCl-B6 (OSeB610). Blood samples were collected at each oestrus (long-term profiles), and daily from day -4 to +3 (slaughter) of the fourth oestrus (peri-oestrus profiles) after which liver, kidneys, and ovaries were collected. For long-term profiles, CONT had lower blood Se than Se-supplemented gilts (p<0.01) and OSe was higher than MSe (p<0.01). Lower erythrocyte pyridoxal-5-phosphate was found in B60 than B610 (p<0.01). No treatment effect was observed on GPX activity. For peri-oestrus profiles, treatment effects were similar to long-term profiles. Treatment effects on liver Se were similar to those for long-term blood Se profiles and OSe had higher renal Se concentrations than MSe gilts (p<0.01). Gene expressions of GPX1, GPX3, GPX4, and selenocysteine lyase in liver and kidney were greatest in OSeB610 gilts (p<0.05). These results suggest that dietary B6 modulate the metabolic pathway of OSe towards the GPX system during the peri-oestrus period in pubertal pigs., (Crown Copyright © 2015. Published by Elsevier GmbH. All rights reserved.)

Selenium is an essential element for the normal cellular function of living organisms. However, selenium is toxic at concentrations of only three to five times higher than the essential concentration. The inorganic forms (mainly selenite and selenate) present in environmental water generally exhibit higher toxicity (up to 40 times) than organic forms. Therefore, the determination of low levels of different inorganic selenium species in water is an analytical challenge. Solid-phase extraction has been used as a separation and/or preconcentration technique prior to the determination of selenium species due to the need for accurate measurements for Se species in water at extremely low levels. The present paper provides a critical review of the published methods for inorganic selenium speciation in water samples using solid phase extraction as a preconcentration procedure. On the basis of more than 75 references, the different speciation strategies used for this task have been highlighted and classified. The solid-phase extraction sorbents and the performance and analytical characteristics of the developed methods for Se speciation are also discussed., (Copyright © 2013 Elsevier B.V. All rights reserved.)

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Selenium pollution in water is a worldwide issue. Se(IV) and Se(VI) are mainly found in contaminated water due to their high solubility and mobility; their presence poses a serious risk as they can severely harm human health. Although iron oxide and hydroxide nanoparticles can be efficient candidates for the removal of selenium oxyanions due to their high adsorption capacity, the role of each iron species has not been fully elucidated. Furthermore, iron species are often found to be less effective for Se(VI) than Se(IV). The challenge and novelty of this study was to develop a carbon material impregnated with different iron phases, including oxides (magnetite/hematite) and hydroxides (goethite/lepidocrocite) capable of removing both Se(IV) and Se(VI). Since the phase and morphology of the iron nanoparticles play a significant role in Se adsorption, the study evaluated both characteristics by modifying the impregnation method, which is based on an oxidative hydrolysis with FeSO4 7H2O and CH3COONa, and the type of carbonaceous support (activated carbon or sucrose-based carbon foam). Impregnated activated carbons provide better removal efficiencies (70–80%) than carbon foams (<40%), due to their high surface areas and point zero charges. These results show that the adsorption of Se(VI) is more favorable on magnetic oxides (78%) and hydroxides (71%) than in hematite (<40%). In addition, the activated carbon decorated with magnetite showed a high adsorption capacity for both selenium species, even in alkaline conditions, when the sorbent surface is negatively charged. A mechanism based on the adsorption of inner-sphere complexes was suggested for Se(IV) immobilization, whereas Se(VI) removal occurred through the formation of outer-sphere complexes and redox processes. [ABSTRACT FROM AUTHOR]

Previous studies indicated that the antioxidant and water balance capacity played important roles in improving the vase life of cut flowers. As a trace element, selenium (Se) has been proven to play an important role in extending the vase life of lily cut flowers. However, there is still no report on the effects of Se on the vase life of other cut flowers. In this study, we explored the role of inorganic selenium, named sodium selenite (Na2 SeO3 ), in improving the vase life of Eustoma grandiflorum cut flowers. Compared with the control (distilled water) and the other Na2 SeO3 concentrations, 4.0 mg/L Na2 SeO3 significantly increased the superoxide dismutase, catalase, ascorbate peroxidase glutathione reductase, glutathione peroxidase and glutathione S-transferase activities, and decreased the malondialdehyde content and the electrolyte leakage. Meanwhile, compared with the control and the other of Na2 SeO3 concentrations, 4.0 mg/L Na2 SeO3 significantly increased the soluble sugar, proline and soluble protein contents, relative water content, average fresh weight change rate and average water balance value. The above results imply that Na2 SeO3 showed an important role in strengthening the antioxidant capacity and maintaining the water balance. Besides, 4.0 mg/L Na2 SeO3 significantly increased the flower diameter and the vase life. The above findings suggested that Na2 SeO3 extended the vase life and the ornamental value of E. grandiflorum cut flowers by enhancing the antioxidant capacity and water balance, which provides new knowledge for the application of Na2 SeO3 in improving the fresh keeping of E. grandiflorum cut flowers. [ABSTRACT FROM AUTHOR]

This study was aimed to investigate the effect of in-ovo injection with vitamin E and selenium during the incubation and post-hatching period. 360 fertilized eggs of Ross 308 broiler breeders were incubated, then distributed on 10th day into three groups (120 eggs/group). 1st group: uninjected eggs, 2nd group: eggs were injected with 0.1 ml deionized water/egg in the chorioallantoic cavity, and 3rd group: eggs were injected with 0.1 ml/egg of Introvit-E-Selen in chorioallantoic cavity. After hatching, 270 chicks were randomly distributed into six groups, and reared until 42 days aged as follows: birds in 1st, 3rd and 5th groups drinks tap water only (free from any addition), while birds of other groups, were reared on drinking water supplemented with 12.5 mg vitamin E and 500 µg sodium selenite/liter water. Results showed a significant increase in hemoglobin, lymphocytes% and serum globulin, and a significant decrease in packed cell volume%, heterophils%, heterophils/lymphocytes ratio, glucose, cholesterol, triglycerides and albumin concentration as compared with control. In conclusion, vitamin E and selenium have enhanced some immunological aspects and reduced stress, as well as a number of hematological parameters of broiler chicks, also, the continuity of Vit.E)Selenium addition led to continuous improvement of physiological parameters, and when it stopped, the values of those parameters were retracted [ABSTRACT FROM AUTHOR]

Flavonoids from Ginkgo biloba have antioxidant and free radical scavenging activity. In the present study, we used different concentrations of OS (organic selenium), NS (nano-selenium), and IS (inorganic selenium) to treat the 2-year-old Ginkgo seedlings and studied the effects of different concentrations of selenium treatment on the physiological indexes and flavonoid content of Ginkgo at different growth stages. Our results showed that the content of chlorophyll, soluble sugar, and total flavonoid glycosides in the 1.6-mM NS treatment group increased significantly in July and September (by 43.87%, 59.92%, and 43.99% and 13.86%, 18.60%, and 35.04%), compared to the control respectively, all P < 0.05. To further analyze the changes of flavonoid content and gene expression levels in Ginkgo leaves, transcriptome sequencing analysis was performed on the treated seedlings. Sequencing analysis results showed that NS could promote PAL, COMT, CAD, and F6H gene expression levels in the flavonoid synthesis pathway; OS up-regulates the CCR and HCT genes. IS promotes the expression of C3'H, CCoAOMT, CYP, DFR, and HCT genes. Furthermore, the increase of key genes and enzyme levels promotes the increase of total flavonoid content. These data suggest that the appropriate concentration of OS and NS can promote the expression level of flavonoid synthesis genes and further promote the increase of total flavonoid content in Ginkgo leaves, which is beneficial to the medicinal value of Ginkgo extract. [ABSTRACT FROM AUTHOR]

Abstract The chemical properties including toxicity of selenium depend on the concentration and chemical structure present in the natural environment. Inorganic selenium is more toxic than organic selenium; thus, the accurate determination of inorganic selenium in various sample has been needed. HG-AAS, HPLC-ICP-MS, and GC-MS are the current methods for the determination of inorganic selenium. However, these methods have the disadvantage of expensive equipment, complicated sample preparation, and long analysis time. LIBS coupled with ion exchange membrane was used for the determination of inorganic selenium. The detection limit of inorganic selenium by the analytical method was 11.21 mg/kg, and the recoveries of 50 and 100 mg/kg Se(VI) were 98.5 % and 101.80 %, respectively. The speciation method is cost-effective, simple, and not labor intensive for the quantitation of inorganic selenium.

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]

[Display omitted] • A 2,3-diaminonaphthalene post-synthetic modified magnetic MOF was fabricated. • The material was applied to the selective extraction of inorganic selenium. • The material exhibited selectivity toward Se(IV) at a pH of 2.5. • LOD and linear range were 8.0 ng/L and 25–8000 ng/L, respectively. • The analytical applicability was confirmed in various food, and water samples. In this work, a 2,3-diaminonaphthalene post-synthetic modified magnetic metal–organic framework was fabricated for fast and selective determination of inorganic selenium in real food and water samples. The results exhibited that selenium (IV) is adsorbed by the nano-material at a pH of 2.5, and in this way, selenium (IV) can be quantified selectively. After identifying the nanosorbent with FT-IR, CHNS, XRD, SEM, TEM, VSM, and BET surface analysis, parameters affecting the retention and desorption were optimized. Under optimal conditions, the detection limit of 8 ng/L was achieved for selenium (IV), and the method's precisions were less than 12.5 % intra-day RSD% and < 14.4 % for inter-day RSD%. The highest adsorption capacity was obtained as 264 mg/g. Finally, the desired adsorbent was used to extract and determine selenium species in water samples and total selenium in food samples. One of the most important advantages of the present method is its speed, ease, time-saving, and high accuracy. [ABSTRACT FROM AUTHOR]

This study aims to investigate the effects of different selenium (Se) sources on the growth performance of Chinese broilers and provide a scientific rationale for adding Se additives to broiler feed. Relevant studies that meet standard inclusion criteria were identified and extracted from China National Knowledge Infrastructure and Wanfang and Chinese Scientific Journal (VIP) databases. A total of 9 studies with 539 subjects were included. A meta-analysis was performed with STATA15.0 to estimate the combined standardized mean difference (SMD) with a 95% confidence interval (95% CI). Heterogeneity test of articles was examined by Q-test, and the results showed that P values of feed conversion ratio, average daily gain (ADG), and average daily intake were all less than 0.05, suggesting a strong heterogeneity among the selected literature. Therefore, the random effect model is selected to calculate the SMD of the three indexes. The combined SMDs (95% CI) of feed:gain, ADG, and average daily feed intake (ADFI) were −0.39 (−1.03, 0.25), 0.26 (−0.29, 0.81), and −1.45 (−3.09, 0.20), respectively, and the P values were all less than 0.05. This study shows that the absolute differences in the growth performance (feed:gain, ADG, and ADFI) of broilers fed with either organic or inorganic Se supplements at the same dose were quite small. The P values of Egger's test were 0.770, 0.089, and 0.426, respectively, for the above indexes, showing no significant publication bias. Sensitivity analysis ensured the stability and reliability of the results. In summary, the effects of organic and inorganic Se in feed on the growth performance of broilers are statistically equal. [ABSTRACT FROM AUTHOR]

The chemical properties including toxicity of selenium depend on the concentration and chemical structure present in the natural environment. Inorganic selenium is more toxic than organic selenium; thus, the accurate determination of inorganic selenium in various sample has been needed. HG-AAS, HPLC-ICP-MS, and GC-MS are the current methods for the determination of inorganic selenium. However, these methods have the disadvantage of expensive equipment, complicated sample preparation, and long analysis time. LIBS coupled with ion exchange membrane was used for the determination of inorganic selenium. The detection limit of inorganic selenium by the analytical method was 11.21 mg/kg, and the recoveries of 50 and 100 mg/kg Se(VI) were 98.5 % and 101.80 %, respectively. The speciation method is cost-effective, simple, and not labor intensive for the quantitation of inorganic selenium. [ABSTRACT FROM AUTHOR]

• Lactic acid bacteria convert sodium selenite into organic selenocysteine and elemental Nano-selenium. • Lactic acid bacteria were selected on their ability to grow in a sodium selenite medium and to convert selenite to organic and Nano-Se. • The ability of lactic acid bacteria to act as silage inoculants was not compromised by the addition of sodium selenite. • Lactic acid bacteria inoculants can convert sodium selenite in silo to supplement livestock with organic and predominately Nano-Se. Selenium (Se) is a non-metallic trace element essential for normal cellular function, which has been linked with reduced risk of cancer, cardiovascular disease, cognitive decline and thyroid disease in humans. Se deficiency in livestock is associated with white muscle disease, retained placenta, ill-thrift and mastitis. Where Se status or bioavailability from the soil for plants is poor, livestock rely on supplemental Se in their diets predominantly as either sodium selenite (inorganic form) or selenised-yeast (organic form). As lactic acid bacteria (LAB) have been shown to incorporate Se as either organic or elemental (Nano-Se) there may be potential to use silage inoculant bacteria to improve the Se status of feed to provide the Se requirements of livestock. We screened twenty-seven LAB in MRS broth in the presence of sodium selenite for growth and uptake of Se as organic (selenocysteine and selenomethionine), inorganic (selenite and selenate) or/and Nano-Se, with the aim to identify potential candidates for a mini-silo study. Sodium selenite addition into the growth medium of LAB reduced growth rates but also resulted in the conversion of the inorganic sodium selenite into predominately Nano-Se and small quantities of organic-Se. Based on a rank analysis of growth and ability to take up (total Se content) and convert inorganic Se (Nano and organic Se content), three LAB were selected for further investigation as silage inoculants: L. brevis DSMZ (A), L. plantarum LF1 (B), and L. plantarum SSL MC15 (C). Each LAB was used as an inoculant within a grass mini-silo trial, either cultured in the presence of sodium selenite before inoculation or sodium selenite added to the inoculum at inoculation versus controls with no Se. The addition of sodium selenite either into the growth media of LAB or applied at inoculation of grass silage did not interfere with the ability of the LAB to act as a silage inoculant with no difference in silage fermentation characteristic between LAB with no Se added. The addition of sodium selenite either to the LAB growth medium or at inoculation resulted in the conversion of sodium selenite into Nano-Se and organic-Se (Nano-Se, ca. 103 higher than organic), as previously shown in the screening trial. There was no difference between the three LAB for incorporation of Se or in silage quality, indicating the potential to develop silage inoculants to increase the bioavailable form of Se (elemental and organic) to livestock through conversion of inorganic forms during ensiling. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the effect of higher amount of inorganic selenium (Na2SeO3) on productivity parameters and meat quality of pigs for fattening. Sixty 62-d-old pigs (Landrace x Yorkshire (mother) and Pietrain x Duroc (father)) for fattening which were individually weighed and were randomly assigned to 2 dietary treatments with 2 replicate stalls of 15 pigs each. The pigs were fed for 13 weeks ad libitum with a standard wheat-barleysoybean meal compound diet supplemented with 0.3 mg/kg Na2SeO3 and 75 mg/kg vit. E (Control group) and with 0.5 mg/kg Na2SeO3 and 75 mg/kg vit. E (Experimental group). Meat traits in live pigs were measured by ultrasonic equipment Piglog 105. The samples for the analysis of selenium were taken from the M. longissimus dorsi between 12 and last rib and from the liver. Chemical composition of breast meat was being determined by standard methods. The results of conducted trial showed, that the addition of 0.5 mg/g of sodium selenite in the diets of fattening pigs didn't affect productivity parameters, chemical meat composition, accumulation of selenium in the meat tissue, but significant improved the muscularity of pigs. [ABSTRACT FROM AUTHOR]

We describe a method for the determination of inorganic selenium in water samples via gas-phase chemiluminescence (GPCL). Se(IV) was first derivatized with 4-nitro- o-phenylenediamine to form 5-nitropiazselenol. The latter was decomposed by persulfate through photocatalytic oxidation to give Se(VI), which was reduced to Se(IV). Selenium hydride was generated from Se(IV) through reduction with sodium borohydride and then preconcentrated using cryotrapping. The cryotrapped hydride was evaporated and carried to a reaction chamber by a stream of helium, where it produced GPCL as a result of ozonation. The method exhibits a wide linear calibration range (from 0.5 μg L to 1.0 mg L) with a detection limit of 0.12 μg L (for n = 11), and a relative standard deviation of 3.90 % (at n = 11) at 5.0 μg L level of selenium. The method was applied to the determination of inorganic selenium in water samples and gave satisfactory results. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: Herein, ultrasound-assisted emulsification microextraction (USAEME) and dispersive liquid–liquid microextraction (DLLME) methods based on applying low-density organic solvents have been critically compared for the speciation of inorganic selenium, Se(IV) (selenite) and Se(VI) (selenate) in environmental water samples by gas chromatography-flame ionization detection (GC-FID). At pH 2 and T =75°C for 7min, only Se(IV) was able to form the piazselenol complex with 4-nitro-o-phenylenediamine. Piazselenol was extracted using an extraction solvent and was injected into a GC-FID instrument for the determination of Se(IV). Conveniently, Se(VI) remained in the aqueous phase. Total inorganic selenium was determined after the reduction of Se(VI) to Se(IV) and prior to the above procedures. The Se(VI) concentration was calculated as the difference between the measured total inorganic selenium and Se(IV) content. The effect of various experimental parameters on the efficiencies of the two methods and their optimum values were studied with the aid of response surface methodology and experimental design. Under the optimal conditions, the limit of detections (LODs) for Se(IV) obtained by USAEME-GC-FID and DLLME-GC-FID were 0.05 and 0.11ngmL−1, respectively. The relative standard deviations (RSDs, n =6) for the measurement 10ngmL−1 of Se(IV) were 5.32% and 4.57% with the enrichment factors of 2491 and 1129 for USAEME-GC-FID and DLLME-GC-FID, respectively. Both methods were successfully applied to the analysis of inorganic selenium in different environmental water samples and certified reference material (NIST SRM 1643e). [Copyright &y& Elsevier]

The aim of the trial was to determine the efficacy of organic Se from Se-enriched yeast in placental transfer to piglets in the conditions of a Czech pig farm. In group I (n = 8) the sows were fed during gestation and lactation a diet supplemented with inorganic Se (sodium selenite, 0.3 mg/kg of Se for the gestation and 0.38 mg/kg of Se for the lactation diet). In group II (n = 8) the diet of the sows was supplemented with organic Se from Se-enriched yeast (0.3 mg/kg of Se for the gestation and 0.38 mg/kg of Se for the lactation diet). Se concentrations in the whole blood, colostrum and milk were higher (P < 0.01) in the group of sows fed with the organic Se form. No differences in GSH-Px activities in the whole blood were found between the two groups of sows. The concentrations of Se in piglet tissues (heart P < 0.05, liver P > 0.01, muscle P > 0.01) were also higher when the organic form was provided. It is concluded that the use of the organic Se from Se-enriched yeast in sows resulted in greater transfer of Se to their progeny, however it did not have a positive effect on the antioxidant system of the organism. [ABSTRACT FROM AUTHOR]

This paper describes the combined use of a new preconcentration method using the Amberlite IRA-743 resin and high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry to determine simultaneously inorganic and organic selenium species in aquatic systems. The developed enrichment procedure, whose accuracy has been checked by recovery tests, is suitable for selenium speciation at environmental levels of 10 ng (Se) l−1. The method has been applied to mineral and freshwater samples. [Copyright &y& Elsevier]