• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1907-1914
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• 2010

A novel catalytic kinetic method is proposed for the determination of Se(IV), Se(VI) and total inorganic selenium in water based on the catalytic effect of Se(IV) on the reduction of bromate by p-nitrophenylhydrazine at pH 3.0. The generated bromine, $Br_2$ or $Cl_2$ plus $Br_2$ in 0.1 M NaCl (or NaBr) environment efficiently decolorized Calmagite and the reaction was monitored spectrophotometrically at 523 nm as a function of time. In this indicator reaction, bromide acted as an activator for the catalysis of selenium (IV) and a reducing agent for selenium (VI) at pH 3.0, which allowed the determination of total selenium. The fixed time method was adopted for the determination and speciation of inorganic selenium. Under the optimum conditions, the calibration graph are linear in the range 1 - 35 ${\mu}gL^{-1}$ of Se(IV) for the fixed time method at $25^{\circ}C$. The detection limit based on statistical $3S_{blank}$/m-criterion was 0.215 ${\mu}gL^{-1}$ for the fixed time method (7 min). All of the variables that affect the sensitivity at 523 nm were investigated, and the optimum conditions were established. The interference effect of various cations and anions on the Se (IV) determination was also studied. The selectivity of the selenium determination was greatly improved with the use of the strongly cation exchange resin such as Amberlite IR120 plus. The proposed kinetic method was validated statistically and through recovery studies in natural water samples. The RSDs for ten replicate measurements of 5, 15 and 25 ${\mu}gL^{-1}$ of Se(IV) and Se(VI) was changed between 2.1 - 4.85%. Analyses of a certified standard reference material (NIST SRM 1643e) for selenium using the fixed-time method showed that the proposed kinetic method has good accuracy. Se(IV), Se(VI) and total inorganic selenium in environmental water samples have been successfully determined by this method after selective reduction of Se(VI) to Se(IV).

• Journal of Animal Science and Technology
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• v.48 no.4
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• pp.603-610
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• 2006

This study was conducted to investigate the feeding effect of selenium provided by different sources on the physico-chemical properties of M. longissimus thoracis. Twenty Hanwoo steers(20～24 months, approximately 613kg) were assigned to 4 different feeding groups of each five, depending on the sources of selenium such as inorganic selenium(sodium selenite), organic selenium(Yeast, USA Sel-Plex), Se-SMC(Se-spent mushroom compost) and the control(no selenium). The selenium level in feed was 0.9 ppm for all groups except the control. Animals were fed with different feeding treatments for 12 weeks and slaughtered at National Livestock Research Institute. The inorganic selenium group had the highest cooking loss(CL. %) and followed by the Se-SMC group and organic selenium group. No significant differences in chemical composition, WB-shear forces, water-holding capacity(WHC) and sensory properties were found among the groups(P>0.05). There were 40% frequencies of grade A in the inorganic selenium group and followed by the organic selenium group(20%). Se-SMC group had 80% of frequencies for grade 1+ and followed by the inorganic selenium group(40%), whereas the organic selenium group and the control group had the 20% frequencies for grade 1+. From the results of this study showed that the selenium sources did not affect chemical composition, WHC and tenderness of Hanwoo steers. However, the inorganic selenium group had the highest cooking loss(%) and lowest pH when compared to the other groups.

• Journal of Practical Agriculture & Fisheries Research
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• v.6 no.1
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• pp.90-101
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• 2004

Se is essential for a number of enzymes that perform important metabolic functions necessary for good health. However, people in many countries do not appear to consume adequate amounts of Se to support the maximal expression of the selenoproteins and Se retention in the body of animals and humans is dependent on the ingested Se source such as organic and inorganic Se. Therefore, this review was discussed to explore metabolic characterization regarding intestinal absorption, bioavailability and selenoprotein synthesis according to animal species such as monogastrics including human beings and ruminants. Generally, organic Se provided to animals is more effective than inorganic Se in body retention for the animal owing to the difference of manner for intestinal absorption. But, Se absorption in ruminants depending on its chemical form still remained questioned by several microbial actions and feeding regimen in the rumen. And Se absorbed through small intestine is utilized for the synthesis of selenoproteins and/or retained as selenoamino acids in the body. Retained Se in the body may be recycled to synthesize selenoproteins as lacked of dietary Se. In conclusion, desirable forms of Se ingestion in the animal may be useful for Se fortification in animal products as well as well being for humans and animals.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.1
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• pp.91-96
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• 1994

This study was conducted to determine the effect of inorganic selenium (Se) sources on rumen bacterial yield, ruminal volatile fatty acid (VFA) production and total tract digestion of timothy hay (Phlewm pratense L.) in Japanese Corriedale wethers. A $3{\times}3$ Latin square design was used with three wethers, three periods and three treatments. In each period, there was 7 d dietary adjustment followed by 5 d total collection of urine and feces. Ruminal fluid samples were obtained at 0, 1, 3, 5 and 7 h postprandially on the final day of the collection period. The three dietary treatments were: (1) without Se supplementation (control); (2) with Se supplementation as sodium selenate; and (3) sodium selenite at a rate 0.2 mg Se/kg dietary DM. The basal diet was timothy hay fed at 2% of body weight/d. Results indicated that there was slight decrease in rumen bacterial yield of animal supplement with inorganic Se, however, differences over the control were insignificant. It was found that Se content of ruminal fluid was negatively correlated (p < 0.05) to rumen bacterial yield. The various VFA contents and acetate and propionate ratio of the different ruminal fluid samples were insignificant across treatment means and the same manner was observed to the different digestibilities (DM, OM, CP, NDF, ADF and NDS). This study concludes that Se supplementation at 0.2 mg Se/kg dietary DM either from sodium selenate or sodium selenite could not significantly influence rumen bacterial functions.

• Animal Bioscience
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• v.35 no.12
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• pp.1948-1956
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• 2022

Objective: This study was conducted to evaluate the effects of selenium (Se) source and level on the physiological response, reproductive performance, serum Se level, and milk composition in gestating sows. Methods: A total of 54 multiparous sows (Yorkshire×Landrace) with average body weight (BW), backfat thickness (BF), and parity were assigned to one of five treatments with 10 or 11 sows per treatment using a 2×2 factorial arrangement with one additional treatment in a completely randomized design. Inorganic or organic Se (IS or OS) sources were added to the diet at 0.30 ppm and 0.50 ppm Se. A non-Se-fortified corn-soybean meal basal diet served as a negative control. Treatments were as follows: i) Control: corn-soybean based diet, ii) IS30: control+inorganic Se 0.30 ppm, iii) IS50: control+inorganic Se 0.50 ppm, iv) OS30: control+ organic Se ppm, and v) OS50: control+organic Se 0.50 ppm. Results: At day 21 of lactation, piglet weight and weight gain in the OS treatments were higher than those in the IS treatments (p<0.05). Meanwhile, adding 0.5 ppm Se also resulted in the same significant differences in piglet BW and weight gain (p<0.05). Colostrum and milk Se concentrations increased (p<0.05) with Se level for both Se sources but were greater when sows were fed organic Se (p<0.05). Except for 24 hours postpartum, the Se concentrations were higher when sows were fed organic Se (p<0.05). Sow serum Se content was greater as Se levels increased from 0.3 ppm to 0.5 ppm at day 110 of gestation, 24 hours postpartum and day 21 of lactation (p<0.05). The pig serum Se concentration increased as the dietary Se level increased (p<0.05) and was higher when the sow dietary Se source was organic (p<0.05). Organic Se 0.5 ppm also had the highest serum Se level at two measured points (p<0.05). Conclusion: Consequently, supplementation with organic Se or 0.5 ppm Se in a gestating diet could improve piglet performance, the Se status of sows and piglets and milk composition, but organic Se at 0.5 ppm is optimal.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.197-199
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• 1987

This paper is investigated on characteristics of photoresist using inorganic a-$Se_{75}Ge_{25}$. The sensitivity of negative photoresist showing insolubility against alkalie solution, with Ag-photodoped, is more prominent than that of positive photoresist used with only a-$Se_{75}Ge_{25}$. It is also showed that the contrast of negative photoresist, ${\gamma}=2.9$, is more prominent than that of positive photoresist, ${\gamma}=1.4$.

• Analytical Science and Technology
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• v.26 no.3
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• pp.182-189
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• 2013

The purpose of this research is to separate and quantitate selenium species in some food samples with HPLC-ICP-MS. Cation exchange chromatography showed efficient separation only for inorganic Se species while reversed phase ion pair chromatography showed good separation for both inorganic and organic Se species. $C_8$ column ($Symmetryshield^{TM}\;RP_8$, 3.5 ${\mu}m$, $4.6{\times}150$ mm) was used with optimum condition of 5% methanol mobile phase, 0.05% of nonafluorovaleric acid ion pairing reagent. Five standard Se species of Se(IV), Se(VI), SeCys(selenocystein), SeMet(selenomethionine) and Se-M-C(seleno methyl cystein) were separated successfully under the optimum condition (mobile phase; 5% methanol, ion-pairing reagent; 0.05% nonafluorovaleric acid, flow rate; 0.9 mL $min^{-1}$). To extract Se species, microwave assisted and enzyme-assisted extraction methods were studied. In enzyme-assisted extraction method, protease I for garlic, protease I plus trypsin for pork and mackerel, and protease XIV for tuna showed the best extraction efficiency. With the optimum condition for each sample, it was found that mostly inorganic Se, SeCys and SeMet are present in the sample studied ranging from few ${\mu}g$ $g^{-1}$ to few tens of ${\mu}g$ $g^{-1}$.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.3
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• pp.435-444
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• 2003

In 1957, Schwarz and Foltz discovered that selenium (Se) was an essential trace mineral and nutritionists then started extensive studies to figure out the metabolic function of this element which has been called as toxic mineral. The discovery that glutathione peroxidase (GSH-Px) contained Se demonstrated a biochemical role for Se as an essential trace element. The major physiological function of Se containing GSH-Px is thought to maintain low levels of $H_2O_2$ and other hydroperoxides in the cell to prevent tissues from peroxidation damages. It is known that the GSH-Px activity is increased when animals were fed high dietary levels of Se. Chemical properties of Se have much in common with sulfur (S) therefore Se would follow the sulfur pathways in its metabolism in animal body. Two sources of Se are available for supplementation of Se in animal feed. Inorganic Se can also exist in selenide (-2), elemental (0), selenite (+4) and selenate (+6) oxidation state with other minerals. When sulfur in S containing amino acids is replaced by Se, organic Se can be made and named "eleno"prior to the name of S containing amino acid, i.e. selenomethionine. Selenium deficiency affects humans as well as animals and dysfunctions such as exudative diathesis, retained placenta, mastitis, liver necrosis, Keshan disease, numerous diseases and cancer. From several centuries ago, Se toxicity was recognized in various animal species and much of the current toxic Se levels has been established largely based upon the controlled toxicity studies used inorganic Se. Toxic effects of Se in animal result in reduced feed intake, growth retardation, ataxia, diarrhea, alopecia and sloughing of hooves. However, several experiments demonstrated that Se deficiencies or toxicities were varied by dietary Se levels and sources. Recent studies demonstrated that the incidence of colorectal and prostate cancer was reduced by approximately 50% when humans consumed 200 ${\mu}g$ of Se daily.

• Journal of the Korean Chemical Society
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• v.63 no.5
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• pp.335-341
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• 2019

Spirulina was cultured in Selenium solution and the total concentration was determined with isotope dilution technique. Low-molecular-weight-Selenium species for the water extract of Spirulina were separated and quantified with HPLC ICP/MS. Water extraction was used first and then protein enzyme (protease XIV) was used to digest and extract for the Se species in both water extract and residue. The total Se was $414.9{\pm}4.0{\mu}g\;g^{-1}$ and 77% existed in water extract while 22% remained in residue. Se species in supernatant was mostly inorganic selenate ($222.7{\mu}g\;g^{-1}$). After hydrolysis of protein, SeCys ($15.20{\mu}g\;g^{-1}$) and SeMet ($12.13{\mu}g\;g^{-1}$) were found. In residue, SeCys and SeMet were found with little inorganic Se. After protein hydrolysis of residue, more of Selenoamino acids SeCys ($9.35{\mu}g\;g^{-1}$) and SeMet ($18.23{\mu}g\;g^{-1}$) in addition to MeSeCys ($1.5{\mu}g\;g^{-1}$) were found. It is thought that inorganic selenium is mostly adsorbed on the surface of spirulina and can be easily removed by a simple distilled water extraction while most of organo-seleniums are remained in residue.

• Korean Journal of Animal Reproduction
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• v.27 no.2
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• pp.143-152
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• 2003

The objective of this study were to investigate the effects of Se and Vit. E administration on blood chemical values and Vit. E concentrations of serum in calves born from Hanwoo dams injected Se and Vit. E at late pregnancying periods. The effects of Se and Vit. E administration of blood chemical values in calves born from Hanwoo dams injected Se and Vit. E at the last month of pregnancying periods were examined. In albumin concentration of blood, the Vit. E 2000IU group were slightly higher than other groups and the cholesterol concentrations were also higher in Vit. E 15001u group than other groups. But, another components examined of blood chemical values were not significantly different in all experimental groups. The blood chemical values in calves born from Hanwoo dams administrated Se and Vit. E at two months before parturition were examined. However, there were not significantly different in all experimental groups in concentrations of albumin, cholesterol, BUN, creatinine, glucose, inorganic phosphorous, calcium, total protein and triglycerides. The concentrations of serum Vit. E in calves born from Hanwoo dams administrated Se and Vit. E at 30 and 15 days before parturition were examined. The concentrations of Vit. E in serum were higher in treatment groups than in control group(P>0.05). The concentrations of serum Vit. E in calves born from Hanwoo dams administrated Se and Vit. E at 60 days before parturition were examined, the concentrations of Vit. E in serum were slightly higher in groups administrated than in control group(P>0.05), but there were not significantly difference in all experimental groups.