• Bulletin of the Korean Chemical Society
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• 제31권7호
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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).

• 분석과학
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• 제8권4호
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• pp.419-425
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• 1995

A method has been investigated for the determination of selenium and tellurium in Ginseng, Ganoderma and Garlic using hydride generation atomic absorption spectrometry(HG-AAS). The concentration effects of hydrochloric acid and sodium tetrahydroborate on the hydride generation for the determination of selenium and tellurium were investigated. The method of sample decomposition was also investigated using various mineral acids, such as nitric, perchloric and sulfuric acid in the closed system, and foreign ion effects containing in the samples were studied. The calibration curves of selenium and tellurium were obtained in the range of 0~40 ppb. The detection limits(S/N=2) of selenium and tellurium are 0.1 and 0.2 ppb. Analytical data of selenium and tellurium in Garlic, Ganoderma and Ginseng are 289, 296 and 198 ng/g for selenium and 146, 127 and 110 ng/g for tellurium, respectively.

• Journal of Nutrition and Health
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• 제36권5호
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• pp.491-499
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• 2003

Selenium is a strong antioxidant trace mineral, scavenging free radicals. The prevalence of chronic degenerative diseases is increasing in Korean adults with increasing age. The increased cell damage from free radicals has been implicated in the etiology of these diseases, and evidence is accumulating that the low selenium status that comes with advanced aged is involved in the prevalence of age-associated diseases. However, little is known about the selenium status of Koreans, its age-related change and its relationship to dietary nutrient intake. In this study, the serum selenium levels of healthy adult females according to life cycle and its association with blood albumin levels and nutrient intake were examined. Serum selenium level was measured with the Huwo research reactor using the neutron activation analysis method (NAA). The overall proportion of women with selenium deficiency, serum selenium concentrations below 7.0 $\mu\textrm{g}$/dl, was 9.4%. The average serum selenium levels were 12.39 $\mu\textrm{g}$/dl, 9.45 $\mu\textrm{g}$/dl and 9.16 $\mu\textrm{g}$/dl in the young adult, middle-aged and elderly groups, respectively, showing a reduction of selenium status with advancing age. Selenium deficiency was seen only in the elderly group. Generally, serum selenium levels positively or negatively correlated with nutrient intake, but these association patterns differed depending on the age. The nutrients that showed positive correlations with selenium levels were proteins and phosphate in the young adult group (p < 0.05, p < 0.05), and total calcium, potassium and vegetable-origin calcium in the middle-aged group. Vitamin C and fiber were the negative correlated nutrients with serum selenium levels in the elderly group (p < 0.05, p < 0.05). Multiple stepwise regression analysis of the determining factors responsible for selenium status showed that age and serum albumin levels were important factors which explained up to 26.9% variances in serum selenium levels. The average selenium concentrations of Korean adult female subjects were above the deficiency levels in all three age groups. There was a tendency toward decreasing selenium levels as the age of the subjects increased. The factors with the strongest in-fluence on selenium status in healthy adult Korean females were age and serum protein status. (Korean J Nutrition 36(5): 491~499, 2003)

• 한국환경보건학회지
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• 제15권2호
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• pp.85-95
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• 1989

An experimental study on the selenium effects on toxicity of lead (4ppm intraperitoneal injection) in adult male rats of Spragne-Dawley strain was performed. This study was carried out to reveal the selenium effects concerning treatment and prevention of lead intoxication and differences of the selenium effects according to the administration method between oral and subcutanous. The changes of body weight, liver and kidney weight per body weight, hemoglobin values, hematocrit values, TBA values in serum, and $\delta$-ALAD activity in blood were determined. The results were as follows 1. There were no significant differences among groups about the change of body weight. 2. In the liver weight per body weight, the group of Pb administration after the oral administration of selenium was significantly high, different from the group of Pb administration alone (p < 0.05). 3. There .were no significant differences among groups about the kidney weight per body weight. 4. On the hemoglobin values, the group of Pb administration with selenium was significantly high,different from the group of Pb administration alone (p < 0.05). 5. There were no significant differences among groups about the hematocrit values. 6. On TBA values in serum, all the selenium treated groups were significantly low different from the group of Pb administration alone (p < 0.01). 7. On $\delta$-ALAD activity, all selenium treated groups were significantly high different from the group of Pb adminsitration alone (p < 0.01). Considering from the results of this experiment, selenium seems to reduce Pb toxicity and preventive administration of selenium seems to be also effective. And the difference of selenium effect according to the administration method between oral and subcutaneous could not be found.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 센서 박막재료 반도체재료 기술교육
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• pp.51-54
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• 2002

Recently, due to its better photosensitivity in X-ray, the amorphous selenium based photoreceptor is used on digital direct method conversion material. Compared to other photoconductive material, amorphous selenium has good X-ray response characteristic and low leakage current. It has many parameters of detecting X-ray response on selenium. Among of them, it is well known that manufacture of a-Se is the most basic element. In this paper, we fabricated two types of amorphous selenium sample which had time variable. The one was fabricated continuous deposition sample and the other was step by step sample. Thickness of sample was $300{\mu}m$ and top electrode was evaporated gold. We investigated the leakage current and photo current of them and analysed their electrical characteristics. For analyzing morphology of samples, SEM and surface was pictured. We found that step by step deposition method could be applied for novel fabricating amorphous selenium film.

• Applied Microscopy
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• 제26권4호
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• pp.411-420
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• 1996

A zinc-specific method (selenium method) has been employed to identify the zinc-containing cells in the cerebellum of the rats. When rats were allowed to survive 24 hours after the sodium selenite administration, zinc selenide reaction products formed in zinc-containing cellular boutons are retrogradely transported to the somata of those boutons. And the zinc selenide products accumulated in somata of the cells can be rendered visible by silver amplification of developer. Zinc-containing cells identified by the method were Bergmann glial and granule cells. Labeled zinc-containing cells were absent in molecular layer and white matter of the cerebellum. In ultrastructural level, the zinc selenide products were located in lysosomes of somata of the zinc-containing cells.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.853-856
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• 2002

Present. direct method x-ray conversion detector is studied by abroad medical instrument and country with amorphous Selenium. And we search the method for large area x-ray detector. Amorphous-Selenium based photoreceptor is widely used on the X-ray conversion materials. But amorphous-selenium based x-ray conversion detector is broken by high voltage and leakage defect point. In this paper, We investigated top-electrode distance rate to improve defect point and high voltage broken. The result to appoint to made large area x-ray conversion detector with base data.

• Preventive Nutrition and Food Science
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• 제1권2호
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• pp.230-233
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• 1996

The purposes of this study was to investigate selenium content of human milk and selenium intake of breast-fed infants at each period of lactation longitudinally. The human milk intake in breast-fed infants was measured by test weighing method from 20 lactating mothers at 1,2 and 3 months postpartum. Selenium content in the milks was determined by atomic absorption spectrophotometry with hydride generation after wet digestion of samples. Selenium intake in breast-fed infants was calculated by multiplying human milk intakes by selenium contents. The milk intakes were 640, 726 and 715g/day at 1,2 and 3 months postpartum. The selenium contents in human milk were characterized by a pattern of slight decline with advancing stage of lactation;13.1, 11.5 and 9.8$\mu\textrm{g}$/L at 1,2 and 3 months during lactation. There was a large individual variation at any stage of this study. The mean dietary selenium intakes in breast-fed infants were 8.38, 8.32 and 6.97$\mu\textrm{g}$/day at 1,2 and 3 months postpartum, respectively. The mean daily intakes on a body weight basis were gradually decreased during the course of lactation.

• 약학회지
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• 제29권3호
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• pp.144-151
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• 1985

Cathodic stripping voltammetric determination of traces of selenium in plant samples was studied. Stripping peak of selenium (IV) from Cu-Se intermettalic deposit in acidic media containing copper (II) ion is specific, highly sensitive and well defined, is successfully used for the quantitative determination of selenuin down to the level of 1ng/ml. Sample is burnt in a calorimeter bomb under the oxygen pressure of 40atm. and the selenium is absorbed in 0.1M NaOH. After the solution is filtrated, concentrated and acidified with HCl, then passed through a column of cation exchange resin in the $H^{+}$ form(Dowex 50X-8). The column eluate is analyzed for selenium by differential pulse cathodic stripping voltammetric method. Analytical results of selenium for NBS SMR is well agreement with the certified values. Results are given for a series of plant materials.

• 한국응용과학기술학회지
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• 제5권2호
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• pp.17-28
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• 1988

This experiment is carried out to study alteration of phospholipid compoent in liver, kidney, testis, and brain tissues of male rats which are fed selenium added high fat diets for 7 weeks. The phospholipids of these tissues are analyzed by TLC method. The results are as follows. 1. The growth rate and food intake levels are not affected by selenium-added high fat diets. 2. The levels of total cholesterol, total lipid and TBA are lower in selenium-added diets than selenium free diets 3. The total phospholipid levels of each tissue are kidney > brain > testis > liver and the levels of phospholipid component are Le>Sph>Ce>LLe for kidney and liver, Le>Sph>LLe>Ce for testis and brain.