• Title/Summary/Keyword: 미량 화학

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Determination of La in $U_3Si/Al$ Spent Nuclear Fuel by Ion Chromatography-Inductively Coupled Plasma-Mass Spectrometry (Ion Chromatography-Inductively Coupled Plasma-Mass Spectrometry에 의한 $U_3Si/Al$ 사용후핵연료 중 La의 분리 및 정량)

  • Han, Sun Ho;Choi, Kwang Soon;Kim, Jung Suk;Jeon, Young Shin;Park, Yang Soon;Jee, Kwang Yong;Kim, Won Ho
    • Analytical Science and Technology
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    • v.13 no.5
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    • pp.601-607
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    • 2000
  • Lanthanum has been used as one of the burnup monitor in spent nuclear fuel. $U_3Si/Al$ spent nuclear fuel contains small amount of La in high concentration of U and Al. Therefore, chemical separation of La is required to remove matrix elements. At first, ion chromatography (IC) and inductively coupled plasma systems were installed in radiation shielded glove box to handle the radioactive samples. Retention behavior of uranium, aluminum, lanthanum and some interesting fission products (Sr, Zr, Y, Mo, Ru, Pd, Rh, Cs, Ba, Ce, Pr, Nd, Sm, Eu and Cd) was investigated using the CG10 column and ${\alpha}$-HiBA eluent. As all elements were eluted earlier than lanthanum in 0.2 M ${\alpha}$-HiBA eluent, a portion of U and Al was directly passed to waste using a three way valve between the column and the nebulizer. Thus it was possible to determine the lanthanum in a high concentration of U and Al matrix. Retention time of La was about 12 minutes in this separation condition. Optimum range for the determination of La in $U_3Si/Al$ spent nuclear fuel was $1-10{\mu}g/L$ (ppb) with this system and detection limit was $0.25{\mu}g/L$ in case of $200{\mu}L$ of sample volume.

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Physicochemical Analysis and Sensory Evaluation of Fermented Soy Sauce from Gorosoe(Acer mono Max.) and Kojesu(Betula costata T.) Saps (고로쇠 및 거제수나무 수액 간장의 이화학적 분석 및 관능 평가)

  • Choi, Sun-Young;Sung, Nak-Ju;Kim, Haeng-Ja
    • The Korean Journal of Food And Nutrition
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    • v.19 no.3
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    • pp.318-326
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    • 2006
  • Soy sauce was prepared with the addition of Gorosoe and Kojesu saps instead of tap water to make ordinary soy sauce, respectively. The changes of free sugar, organic acid, mineral, amino acid and nucleotides and other compounds during the fermentation of soy sauce were assessed. The free sugar were found to be fructose, glucose, galactose and sucrose in soy sauce of saps but sucrose was not detected in ordinary soy sauce. Galactose contents were dominant free sugar in all samples. The contents of butyric acid were dominant among 7 kinds of organic acid while fumaric acid was trace amount during the fermentation of soy sauce. The contents of potassium and phosphorus among 13 kinds of minerals were dominant during the fermentation of soy sauce. In the amino acid composition of soy sauce, dominant amino acid was glutamic acid(185.6${\pm}$1.0 mg/100 ml above), but proline and arginine were not detected. AMP detected above 7.5${\pm}$O.2 ${\mu}$mol/100 ml was dominant while inosine was not detected during the fermentation of soy sauce. The results of sensory evaluation in the fermented soy sauce of Gorosoe was 'liked more' than that of soy sauce of Kojesu and control.

Regeneration of Waste Ferric Chloride Etchant Using HCl and $H_2O_2$ (HCl과 $H_2O_2$를 이용한 폐 $FeCl_3$ 에칭액의 재생)

  • Lee, Hoyeon;Ahn, Eunsaem;Park, Changhyun;Tak, Yongsug
    • Applied Chemistry for Engineering
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    • v.24 no.1
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    • pp.67-71
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    • 2013
  • $FeCl_3$ has been used as an etchant for metal etching such as Fe, Cu, and Al. In the process of metal etching, $Fe^{3+}$ is reducted to $Fe^{2+}$ and the etching rate becomes slow and etching efficiency decreased. Waste $FeCl_3$ etchant needs to be regenerated because of its toxicity and treatment cost. In this work, HCl was initially mixed with the waste $FeCl_3$ and then, strong oxidants, such as $O_2$ and $H_2O_2$, were added into the mixed solution to regenerate the waste etchant. During successive etching and regeneration processes, oxygen-reduction potential (ORP) was continuously measured and the relationship between ORP and etching capability was investigated. Regenerated etchant using a two vol% HCl of the total etchant volume and a very small amount of $H_2O_2$ was very effective in recovering etching capability. During the etching-regeneration process, the same oxygen-reduction potential variation cannot be repeated every cycle since concentrations of $Fe^{2+}$ and $Fe^{3+}$ ions were continuously changed. It suggested that the control of etching-regeneration process based on the etching time becomes more efficient than that of the process based on oxygen reduction potential changes.

Processing of the Intermediate Product (Frozen Seasoned Anchovy Meat) Derived from Anchovy (멸치를 이용한 식품가공용 중간소재의 가공)

  • Oh, Kwang-Soo;Ro, Rack-Hyun;Lee, Eung-Ho;Park, Hee-Yeol
    • Korean Journal of Food Science and Technology
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    • v.21 no.4
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    • pp.498-504
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    • 1989
  • Processing conditions and food components of frozen seasoned anchovy meat products were investigated. The separated anchovy meat was chopped, mixed with 12.8% emulsion curd, 0.5% table salt, 2.0% sugar, 0.4% sodium bicarbonate, 0.2% polyphosphate, 0.2% monosodium glutamate, 0.3% onion powder, 0.1% garlic powder, 0.1% ginger powder, 3.0% soybean protein, and 0.2% sodium erythorbate by remodeled stone mortar. This seasoned anchovy meat was frozen with contact freezer, Packed in a carton box and then stored at $-25{\pm}2^{\circ}C$. The major fat acids of product were linoleic, oleic, palmitic, docosahexaenoic, linolenic, palmitoleic, eicosapentaenoic acid. Amino acid composition of product were mainly consisted of Glu, Asp, Leu, Lys and Ala. The taste compounds of product were IMP 160.0 mg/100g ; free amino acids such as Glu, His, Ala, Leu 503.7 mg/100g ; total creatinine 158.3 mg/100g and small amounts of betaine, TMAO.

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Interpretation of Similarity on Raw Materials and Firing Temperature for Underwater Ceramic Artifacts from Offshore in Taean Mado, Korea (태안 마도해역 출수 도자기의 소성온도 및 원재료의 유사성 해석)

  • Lee, Gyu Hye;Lee, Chan Hee
    • Economic and Environmental Geology
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    • v.53 no.3
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    • pp.307-320
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    • 2020
  • This study focuses on the raw material characteristics, including firing temperature and the similarity of clay body, and making techniques on the underwater ceramics from offshore of Taean Mado, the Republic of Korea. The ceramic specimens include various types of celadons, Buncheongwares and white porcelains with very similar physical characteristics. All the clay bodies composed of same mineral phases within mullite and quartz, while cristobalite were also found in some white porcelains. Also, the geochemical composition of the clay body shows regular behavior properties for all the elements consisting of the celadons and Buncheongwares. In contrast, the irregular properties of trace and incompatible elements were found in white porcelains. Therefore, it is presumed that the white porcelains were made using the clay body with different source from the celadons and Buncheongwares. Notably, some white porcelains in low Th content are assumed to be made with clay formed in a different environments. Meanwhile, most of the ceramics had gone through the firing of 1,200 to 1,300℃, with some celadons fired from 1,150℃ to 1,200℃. Also, it can be interpreted as some white porcelains were fired on even up to 1,500℃.

Effects of Phthalate/Adipate Esters Exposure during Perinatal Period on Reproductive Function after Maturation in Rats (성숙한 랫트의 번식 기능에 있어 프탈레이트/아디페이트 에스테르의 주산기 노출의 영향)

  • ;;;;;;Yamanouchi, K.;Nishihara, M.
    • Journal of Animal Science and Technology
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    • v.48 no.5
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    • pp.651-662
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    • 2006
  • Phthalate esters that are used as plasticizers and also found at low levels in foods such as dairy products are often mentioned as suspected endocrine disrupters. The purpose of the present study is to elucidate whether perinatal exposure to di-n-butyl phthalate(DBP), diisononyl phthalate (DINP) and di-2-ethylhexyl adipate (DEHA) affects several aspects of reproductive function in rats especially sexual differentiation of the brain. To this end, the dams were provided with pulverized soy-free diet containing 20, 200, 2,000 and 10,000 ppm of DBP, 40, 400, 4,000 and 20,000 ppm of DINP, or 480, 2,400 and 12,000 ppm of DEHA from gestational day (GD) 15 to postnatal day (PDN) 21, the day of weaning, and serum sex steroid hormone, gonadotropin levels and sexual behaviors after maturation were assessed. At Postnatal week (PNW) 20-21, serum levels of sex steroids and gonadotropins in both male and female rats, as well as estrous cyclicity in females, were not changed by perinatal exposure to DBP, DINP and DEHA, indicating that these chemicals did not affect sexual differentiation of the brain controlling the endocrine system of hypothalamo-pituitary-gonadal (HPG) axis. On the other hand, inhibitory influences on sexual behaviors, especially on ejaculation in males and lordosis in females, were observed by perinatal exposure to these chemicals. These results suggest that these chemicals may act directly on discrete regions of the hypothalamus regulating sexual behaviors, but not regulating gonadotropin secretion, thereby affect sexual differentiation of the brain with a resultant decrease in sex-specific behaviors in adulthood.

Changes of Lactulose Content during Heat Treatment of Milk (우유의 열처리 및 저장 조건에 따른 Lactulose의 함량 변화)

  • 김철현;백승천;정운현
    • Food Science of Animal Resources
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    • v.22 no.1
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    • pp.50-54
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    • 2002
  • The aim of this work to determine the formation of lactulose during heat treatment process as a contribution to the estabilishment of limits of chemical indicators for different types of heat processed milk and analyze of lactulose for the reconstituted milk added samples. The HTST(75$\^{C}$/15s) and UHT(130$\^{C}$/2∼3s) treatment realized with a pilot plant and heat-treated samples were stroed at 4, 10, 30$\^{C}$ for 4 weeks. Changes in lactulose was evaluated at 7 days intervals. The other heat treatment was sealed in glass tube and heated at 75$\^{C}$ for 10 to 120s and heated at 130$\^{C}$ for 2 to 60s in a thermostatically controlled constant temperature bath of glycerol. The reconstituted milk was made with full fat dry milk that reconstituted with deionized water to 10% total solid, and was added to milk at 10, 20, 30% respectively. The samples processed with a HTST pilot plant showed that lactulose was contained at 1.47∼1.52mg/10()ml and 8.19 ∼8.32mg/100ml for UHT-treated samples. Changes in the lactulose content of heat-treated samples during storage at 4 and 10$\^{C}$ for 4 weeks caused a slight increase, however a noticeable increase was observed at 30$\^{C}$ for 4 week. The glass tube samples showed that high correlations between relative increase in content of lactulose and increasing processing times(75$\^{C}$ : r = 0.986, 130$\^{C}$ : r = 0.987, respectively). Added with reconstituted milk would cause a increase of the lactulose content linear with increasing addition amount(r = 0.982). This results observed for lactulose in commercial milk samples would applied to the detection of chemical changes during heat treatment and illegal use of reconstituted milk.

Chemical Characteristics of Raspberry and Blackberry Fruits Produced in Korea (국내산 나무딸기류 과일의 화학적 특성)

  • Oh, Hyun-Hee;Hwang, Keum-Taek;Kim, Mu-Yeol;Lee, Hee-Kwon;Kim, Sung-Zoo
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.6
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    • pp.738-743
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    • 2008
  • In this study, 20 kinds of raspberries and blackberries, cultivated or wild in Korea, were collected. Weight, moisture content, sugar content, sugar composition, pH, titratable acidity and acid composition of the fruits were determined. Weight of each of the fruits and moisture contents in the fruits were $0.9{\sim}7.8g$ and $26{\sim}62%$, respectively. The sugar contents in the fruit juices were $6.9{\sim}16.9%$ (Brix). The major sugars in the fruits were glucose ($40.7{\sim}84.0%$ (w/w) of the total sugars) and fructose ($6.5{\sim}57.5%$). Sucrose and xylose were also detected in a small quantity. pH and titratable acidity of the berry juices were $2.8{\sim}3.9%$ (w/v, citric acid) and $0.6{\sim}2.9%$, respectively. The major organic acids were citric acid ($14.6{\sim}87.5%$ (w/w) of the total acids) and malic acid ($9.6{\sim}87.1%$). Succinic, tartaric and oxalic acids were also detected in a small amount.

Petrology of the Taeheung-ri Lava in Southeastern Jeju Island (제주도 남동부 태흥리 용암에 대한 암석학적 연구)

  • 윤성효;고정선;박정미
    • The Journal of the Petrological Society of Korea
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    • v.11 no.1
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    • pp.17-28
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    • 2002
  • This study has been designed to elucidate the petrography and geochemical characteristics of the Taeheung-ri lava in southeastern Jeju Island. The lava is divided into the alkaline basalt and tholeiitic basalt. More than 4 layers of tholeiitic basalt are overlain by layers of alkaline basalt. Compared with alkaline basalt, tholeiitic basalt has lower contents of $K_2O$, $P_2O_5$, Ba and Ta, but slight higher contents of $SiO_2$ and CaO. The contents of Ba and Rb of all basalts are enriched, but those of Ni and Cr are depleted compared with primitive mantle compositions. All basalts show inclined chondrite-normalized REE patterns with LREE enriched more than HREE and alkaline basalt has relatively higher. The basalts of this study area are plotted in the field of within plate basalt on the tectonomagmatic discrimination diagram. Tholeiitic basalt has higher ratios of Zr/Nb, Y/Nb, and $Al_2O_3/P_2O_5$ than alkaline basalt. Both tholeiitic and alkaline basalt are similar in their K/Ba ratios. The geochemical data suggest that the parental magma of both basalts might be produced by different degrees of partial melting of similar source mantle. The tholeiitic basalt formed by higher degree of partial melting than the alkaline basalt.

Chemical Components of Gastrodia elata Blume Powder (천마 분말의 화학적 성분)

  • Kim, Hyeon-Ju;Chung, Shin-Kyo;Moon, Kwang-Deog
    • Food Science and Preservation
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    • v.7 no.3
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    • pp.278-284
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    • 2000
  • The chemical components in freeze dried Korean Gastrodia elata blume powder were analyzed. The proximate composition was composed of moisture(2.12%), crude protein (4.41%), crude fat(1.20%), crude ash(2.25%), crude fiber(4.60%) and N-free extract(85.15%). Free sugar was composed of glucose(1,314mg%), sucrose(1,081mg%) and fructose(869mg%). Total organic acid content was 2,095mg% and composed of succinic acid(1,238mg%), citric acid, malic acid, oxalic acid and fumaric acid in the order. Among the 11 fatty acids detected, linoleic acid was the most predominant one and unsaturated fatty acid was 80.55 area percent. 18 and 39 amino acids were detected from total and free amino acid, respectively. Arginine, asparagine, proline and sarcosine were the major components of free amino acid. The content of crude saponin and total phenol were 3,768mg% and 821mg%, respectively. Ascorbic acid(6.4mg%), vitamin B1(1.2mg%), vitamin B2(1.7mg%) and niacinamide(0.2m%) were detected as soluble vitamins of the powder. The content of vitamin A and vitamin E was 1.22mg% and 0.32%, respectively.

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