• 제목/요약/키워드: higher order solution

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A Study of Interference Factor of Analysis Method of Hexavalent Chromium in Soil using UV/VIS Spectrometry and Application of Ion Chromatography (자외선/가시선 분광법을 이용한 토양 중 6가 크롬 분석방법의 방해요인 분석 및 이온크로마토그래피 적용에 관한 연구)

  • Noh, Hoe-Jung;Lee, Myung-Gyu;Lee, Hyeon Seok;Kim, Mira;Kim, Dongho;Kim, Tae Seung
    • Journal of Soil and Groundwater Environment
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    • v.17 no.6
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    • pp.33-42
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    • 2012
  • This study was performed to find the problems according to interference factors (organic matter, pH, Cr, Mn, Fe, clay, and etc.) when we analyzed the hexavalent chromium [Cr(VI)] in soils using UV/VIS spectrometer (US EPA 7196A), attempted to evaluate the domestic applicability of analytical method (US EPA 7199) using IC-UV/VIS spectrometer as alternative method. The recovery rate of certified reference materials was 75.0% (US EPA 7196A) and 101.4% (US EPA 7199) by the analytical methods. As the results of performing QA/QC about US EPA 7199, method detection limit (MDL) and limit of quantification (LOQ) were 0.062 mg/kg, 0.196 mg/kg, respectively. The LOQ of US EPA 7199 was lower than that of the current soil official testing method in Korea (0.5 mg/kg). Cr(VI) contents in 23 soil samples were compared by the analytical methods of EPA 7196A and 7199. Cr(VI) was detected in 13 of 23 soil samples by EPA 7196A, while EPA 7199 was not detected in any soil samples. The Cr(VI) content in 23 soil samples by EPA 7196A was not clearly correlated with Cr, Fe, Mn and clay content in the soil samples. However, the contents of Cr(VI) and organic matter of the soil samples had the highest coefficient of determination ($R^2$) of 0.80. In order to evaluate the correlation between the recovery rates of Cr(VI) and organic matter contents in the soil samples, the recovery rates of 5 soil samples added Cr(VI) standard solution were analyzed by the analytical methods. According to the results, the higher the organic matter contents in soil samples, the lower the recovery rates of Cr(VI) by US EPA 7196, while in case of US EPA 7199, the recovery rates were stable regardless of the organic matter contents.

Chromium(VI) Removal from Aqueous Solution using Acrylic Ion Exchange Fiber (아크릴계 이온교환섬유를 이용한 수중 크롬(VI) 제거)

  • Nam, Aram;Park, Jeong-Ann;Do, Taegu;Choi, Jae-Woo;Choi, Ungsu;Kim, Kyung Nam;Yun, Seong-Taek;Lee, Sanghyup
    • Journal of Korean Society of Environmental Engineers
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    • v.39 no.3
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    • pp.112-117
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    • 2017
  • Ion exchange fiber, PADD was synthesized by the reaction between PAN based acrylic fiber and DETA with $AlCl_3{\cdot}6H_2O$, and was analyzed by FT-IR and SEM to investigate its characteristics. The experimental results of Cr(VI) removal by PADD were better fitted with Langmuir adsorption isotherm, and the maximum uptake value ($Q_{max}$) was calculated to be 6.93 mmol/g. The kinetic data can be well described by Lagergen pseudo-second order rate model. The Cr(VI) adsorption capacity of PADD was 4.11 mmol/g at pH 2, which shows the effect of pH changes on the removal of Cr(VI). The adsorption selectivity of Cr(VI) was higher than phosphate and As(V). Total ion exchange capacity of PADD was 4.70 mmol/g, which was measured by acid-base back titration.

Study on the Thermal Stability of PEDOT/PSS Film Hybrided with Graphene Oxide (그래핀 옥사이드와 복합화한 PEDOT/PSS 필름의 열적 안정성에 관한 연구)

  • Choi, Jong Hyuk;Park, Wan-Su;Lee, Seong Min;Chung, Dae-won
    • Applied Chemistry for Engineering
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    • v.27 no.4
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    • pp.402-406
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    • 2016
  • In order to investigate the thermal stability of electro-conductive poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT/PSS), we have prepared films by casting PEDOT/PSS aqueous solution without using a binding material and measured surface resistances of the films while annealing at $200^{\circ}C$. Electrical properties of films were improved by annealing, and the maximum conductivity ($540S{\cdot}m^{-1}$) after annealing for 2 hrs was found to be approximately 3 times higher than that ($180S{\cdot}m^{-1}$) of the original film. The conductivities, however, dramatically decreased with an increase in annealing time and dissipated after 24 hrs of annealing. On the other hand, PEDOT/PSS films hybridized with graphene oxide (GO) displayed a salient improvement in conductivity by annealing, which was measured to be around $600S{\cdot}m^{-1}$ even after 30 hrs of annealing at $200^{\circ}C$. We tentatively conclude that hybridization with GO enhances the thermal stability of PEDOT/PSS.

Hydrolysis of Isolate Soybean Protein Using Subcritical Water (아임계수를 이용한 분리대두단백질의 가수분해)

  • Hwang, Yun Hee;Cho, Hyung-Yong;Kim, Ko-Rae;Lee, Seok Hoon;Choi, Mi-Jung;Shin, Jung-Kue
    • Korean Journal of Food Science and Technology
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    • v.47 no.6
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    • pp.772-778
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    • 2015
  • Hydrolysis of isolate soybean protein (ISP) using subcritical water (SCW) was conducted to study the feasibility for producing protein hydrolyzate. SCW hydrolysis of SPI suspension (5-15%) was conducted in an electrically heated batch reactor (2 L). The effects of temperature (230 to $270^{\circ}C$) and holding time (10 to 50 min) on the degree of hydrolysis (DH) and the production of amino acids were studied by surface response method. The DH was determined by derivatizing the hydrolyzates with ortho-phthalaldehyde (OPA) solution. It was confirmed that reaction temperature and holding time affected the hydrothermolysis of soybean protein. However, the holding time was less effective on amino acid yield when the temperature was higher than $230^{\circ}C$. In order to achieve optimal yields of amino acids exceeding 43%, the temperature should be within the range between 256 and $268^{\circ}C$ with holding time from 29 to 41 min, respectively. A maximum estimated amino acid yield of 43.5% was obtained at $268^{\circ}C$ for 35 min.

Stability of Anthocyanin Pigment from Juice of Raspberries (나무딸기(복분자(覆盆子)) 과즙색소(果汁色素) Anthocyanin의 안정성(安定性)에 관한 연구(硏究))

  • Park, Jung-Mi;Joo, Kwang-Jee
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.11 no.3
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    • pp.67-74
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    • 1982
  • The effect of various pH levels, temperatures. organic acids, inorganic salts, metal ions on the stability of the anthocyanins pigment (pH 3.7) from the juice of raspberries were investigated. Initial absorption of total anthocyanin was decreased as pH increased from 1.0 to 7.0. Total amount of anthocyanin reached the highest at pH 3.7 and least at pH 7.0. The total anthocyanin content decreased rapidly with the increasing temperature. Many organic acids were found to enrich and stabilize the color density at 520nm in anthocyanin solution (pH 3.7). The hyperchromic effect of saturated n-carboxylic acid increased in the following order; formic acid> acetic acid>n-butyric acid>propionic acid. On the polycarboxylic acid, especially, malic acid showed 550$\sim$930% higher than control group. On the inorganic salts (0.5M), sodium perchlorate had the most hyperchromic effect and followed by sodium sulfate>sodium chloride>sodium phosphate, monobasic. Among the metal ions, both aluminium ion and cupric ion much more accelerated the anthocyanins degradation as compared with other metal ions.

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Characterization of $NH_4\;^+$ and $Zn^{2+}$ Adsorption by Korean Natural Zeolites (한국산(韓國産) 천연(天然) 제오라이트의 암모늄과 아연이온의 흡착(吸着)특성)

  • Kang, Shin-Jyung
    • Applied Biological Chemistry
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    • v.32 no.4
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    • pp.386-392
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    • 1989
  • The adsorption of $NH_4\;^+$ and $Zn^{2+}$ by four Korean zeolites, the major species of which are clinoptilolite, clinoptilolite with mordenite, mordenite with clinoptilolite, and mordenite was measured in different concentrations of solutions of $NH_4\;^+$ and $Zn^{2+}$, and their mixtures. The adsorption of $NH_4\;^+$ was greater than that $Zn^{2+}$ far all samples at the concentrations of the added solutions from $1\;to\;7{\times}10^{-3}N$ and this difference was greater at the higher concentrations. Also, $Zn^{2+}$ adsorption by samples was decreased by the presence of $NH_4\;^+$, but that of $NH_4\;^+$ by the presence of $Zn^{2+}$ was not. The extent of $NH_4\;^+$ selectivity among samples was increased in order of clinoptilolite with mordenite$NH_4\;^+$ adsorbed by six successive equilibrations with the solution containing both $NH_4\;^+$ and $Zn^{2+}$ each at a concentration of $3{\times}10^{-3}N$ were in range from 43.7 to 50.4 me/100g, whereas those amounts of $Zn^{2+}$ were in the range from 6.6 to 17.0 me/100g. It was suggested from these results that mordenite and clinoptilolite, particularly the former, can be used for removal of $NH_4\;^+$ from municipal wastewater and those zeolites treated with wastewater can be applied to agricultural land.

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Changes of Major Constituents by Soaking of Citrus platymamma Peel with Spirit Solution (병귤과피의 주정 침출 중 유용성분의 변화)

  • Lee, Sang-Hyup;Kim, Jong-Hyun;Jeong, Hee-Chan;Yang, Young-Taek;Koh, Jeong-Sam
    • Applied Biological Chemistry
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    • v.50 no.3
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    • pp.154-159
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    • 2007
  • In order to prepare liqueur of Citrus platymamma, 500 g dried peel was soaked in 10 l (5%, w/v) of $30{\sim}95%$ ethanol concentration for 70 days. Changes in pH was $5.19{\sim}4.80$ with 30% ethanol concentration, and the pH was decreased as ethanol concentration decreases for 10 days after soaking. Color a-value was decreased and color b-value was increased according to higher ethanol concentration. Extract was $2.00{\sim}2.19%$ (w/v) with $30{\sim}70%$ ethanol concentration. Acid content was $0.18{\sim}0.21%$ (v/v) with $30{\sim}70%$ ethanol concentration, while $0.13{\sim}0.15%$ (v/v) with 95% ethanol concentration. The contents of fructose and glucose was increased with lower ethanol concentration, and sucrose content was decreased with longer soaking time. Main flavonoids were narirutin, hesperidin, nobiletin, 3,5,6,7,8,3'4'-methoxylated flavone, and tangeretin. Most flavonoids were extracted more than 80% of ethanol for $3{\sim}5$ days soaking. Total polyphenol was $628.8{\sim}711.2$ ${\mu}g/ml$ with $30{\sim}70%$ ethanol concentration for 20 days soaking. Therefore, to prepare Citrus platymamma peel liqueur, it is necessary to soak the material in $50{\sim}70%$ ethanol concentration for 20 days.

Convenient Evaluation of Stored Apple Pollen Viability by Fluorochromatic Reaction (형광염색반응에 의한 장기 저장 사과 화분의 활력 측정)

  • Lee, Hee Jae;Kim, Su-Jin;Kim, Tae-Choon
    • Horticultural Science & Technology
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    • v.17 no.3
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    • pp.337-340
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    • 1999
  • In order to evaluate stored apple pollen viability, in vitro germination test was performed on a microscope slide coated with the culture medium containing fluorescein diacetate (FDA). However, the inclusion of FDA to the culture medium declined pollen germination. Alternatively, the fluorochromatic reaction procedure was tested. The procedure involved dusting pollen grains onto drops of 10% sucrose solution containing 0.002% FDA and allowing them to accumulate fluorescein. Within 30 min after the fluorochromatic reaction, viable pollen grains clearly fluoresced under ultraviolet light. Both the in vitro germination test and the fluorochromatic reaction procedure revealed that stored apple pollen viability was not considerably decreased over storage up to at least 39 months. Of the cultivars examined by both methods, 'Fuji' and 'Senshu' pollen viability was highest, 'Tsugaru' was intermediate, and 'Jonagold' was lowest. The fluorescing percentages appeared approximately comparable to the germination percentages except for the 'Senshu' pollens stored for 3 months, although the fluorescing percentages was slightly higher than the germination percentages. Strong and highly significant correlations were found between the two methods. It can thus be concluded that the fluorochromatic reaction procedure provides a convenient and reliable evaluation of stored apple pollen viability.

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Verification of the Fractions with Strong Estrogenic Activities from Brown Algae (갈조류로부터 에스트로겐 고활성 분획의 검증)

  • Lee, Seung-Woo;Jang, Min-Kyung;Kim, Nam-Young;Jang, Hye-Ji;Lee, Dong-Geun;Kim, Mi-Hyang;Kim, Yuck-Young;Kim, Sung-Gu;Yoo, Byung-Hong;Lee, Sang-Hyeon
    • Journal of Life Science
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    • v.20 no.12
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    • pp.1807-1811
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    • 2010
  • In order to evaluate estrogenic compounds in brown algae, an in vitro test system for the verification of estrogenic activity was applied. Fractions from ethanol extracts of each brown alga were prepared by a systematic fractionation procedure with solvents such as $H_2O$, hexane, butanol and methanol. Aqueous fractions of brown algae showed the highest estrogenic activities. Estrogenic activities of $500\;{\mu}g/ml$ aqueous fractions of Undaria pinnatifida and Laminaria japonica showed almost the same strength as that of $10^{-7}\;M$ standard solution ($17{\beta}$-estradiol). Furthermore, estrogenic activities of $500\;{\mu}g/ml$ aqueous fractions of Ecklonia stolonifera and Porphyra suborbiculate represented higher activities than that of $10^{-8}\;M$ $17{\beta}$-estradiol. These observations suggest that aqueous fractions of all these brown algae are expected to possess estrogenic compounds and could be developed as estrogenic agents for postmenopausal disorder.

Interaction of Resveratrol and Genistein with Nucleic Acids

  • Usha, Subbiah;Johnson, Irudayam Maria;Malathi, Raghunathan
    • BMB Reports
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    • v.38 no.2
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    • pp.198-205
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    • 2005
  • Resveratrol (RES) and genistein (GEN) are the dietary natural products known to possess chemopreventive property and also the ability to repair DNA damage induced by mutagens/carcinogens. It is believed that the therapeutic activity of these compounds could be primarily due to their interaction with nucleic acids but detailed reports are not available. We here explore the interaction of these drugs with nucleic acids considering DNA and RNA as a potential therapeutic target. The interaction of RES and GEN has been analysed in buffered solution with DNA [saline sodium citrate (SSC)] and RNA [tris ethylene diammine tetra acetic acid (TE)] using UV-absorption and Fourier transform infrared (FTIR) spectroscopy. The UV analysis revealed lesser binding affinity with nucleic acids at lower concentration of RES (P/D = 5.00 and 10.00), while at higher drug concentration (P/D = 0.75, 1.00 and 2.50) hyperchromic effect with shift in the ${\lambda}_{max}$ is noted for DNA and RNA. A major RES-nucleic acids complexes was observed through base pairs and phosphate backbone groups with K = $35.782\;M^{-1}$ and K = $34.25\;M^{-1}$ for DNA-RES and RNA-RES complexes respectively. At various concentrations of GEN (P/D = 0.25, 0.50, 0.75, 1.00 and 2.50) hyperchromicity with shift in the ${\lambda}_{max}$ from 260 $\rightarrow$ 263 om and 260 $\rightarrow$ 270 nm is observed for DNA-GEN and RNA-GEN complexes respectively. The binding constant (from UV analysis) for GEN-nucleic acids complexes could not be obtained due to GEN absorbance overlap with that of nucleic acids at 260 nm. Nevertheless a detailed analysis with regard to the interaction of these drugs (RES/GEN) with DNA and RNA could feasibly be understood by FTIR spectroscopy. The NH band of free DNA and RNA which appeared at $3550-3100\;cm^{-1}$ and $3650-2700\;cm^{-1}$ shifted to $3450-2950\;cm^{-1}$ and $3550-3000\;cm^{-1}$ in DNA-RES and RNA-RES complexes respectively. Similarly shifts corresponding to $3650-3100\;cm^{-1}$ and $3420-3000\;cm^{-1}$ have been observed in DNA-GEN and RNA-GEN complexes respectively. The observed reduction in NH band of free nucleic acids upon complexation of these drugs is an indication of the involvement of the hydroxyl (OH) and imino (NH) group during the interaction of the drugs and nucleic acids (DNA/RNA) through H-bonded formation. The interaction of RES and GEN with bases appears in the order of G $\geq$ T > C > A and A > C $\geq$ T > G. Further interaction of these natural compounds with DNA and RNA is also supported by changes in the vibrational frequency (shift/intensity) in symmetrical and asymmetrical stretching of aromatic rings of drugs in the complex spectra. No appreciable shift is observed in the DNA and RNA marker bands, indicating that the B-DNA form and A-family conformation of RNA are not altered during their interaction with RES and GEN.