• Title/Summary/Keyword: LC-UV

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A Study on Contents of Vitamin D in Agricultural Products and Foods (농식품자원의 비타민 D 함량 조사)

  • Ji, Soo-Hyun;Jang, Mi-Young;Choi, Jung-Yeon;Choi, Young-Min;Kim, Young-Gook
    • The Korean Journal of Food And Nutrition
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    • v.28 no.1
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    • pp.143-152
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    • 2015
  • Vitamin D contents in agricultural products and foods were quantified by high performance liquid chromomatography (HPLC) with a UV/Vis detector, using external standard methods. The results were confirmed with liquid chromatography tandem mass spectrometry (LC-MS/MS). After homogenization, samples were hydrolyzed by direct alkali saponification. Thereafter, fat-soluble components were extracted with n-hexane containing 0.01% butylated hydroxytoluene (BHT). Vitamin D contents in cereals were found to be in the range of $1.882{\sim}4.856{\mu}g/100g$. Juda's ear and oak mushroom contained high amounts of vitamin D, at 363.85 and $199.42{\mu}g/100g$ of edible portion, respectively.

A Study of Odorants and Volatiles Released from Pork Belly Meat When Treated by Different Cooking Methods (삼겹살 구이로부터 발생하는 유해물질의 특성 연구)

  • Kim, Bo-Won;Kim, Ki-Hyun;Kim, Yong-Hyun;Ahn, Jeong-Hyeon
    • Journal of Korean Society for Atmospheric Environment
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    • v.30 no.3
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    • pp.211-222
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    • 2014
  • Pork belly meat is one of the most preferred food items for many Korean people. The odorants released from cooking of pork belly meat were measured by three kinds of cooking methods (Charcoal-grill (C), Electric Pan (E), and Gas burner-pan (G)). A total of 16 target compounds including carbonyl compounds, volatile organic compounds, and poly aromatic hydrocarbon were selected and analyzed for comparative purposes. Their emission concentrations were quantified using HPLC-UV, GC-MS, GC-TOF-MS, etc. The gas samples collected by Charcoal-grill cooking showed generally enhanced concentrations of most target compounds among all three kinds of cooking methods. In Charcoal-grill, concentration of benzene, formaldehyde and pyrene went up to 543, 516, and 402 ppb, respectively. It the results are compared in terms of the sum of odor intensity, the highest value (4.25) was also seen from Charcoal-grill. The results of this study confirm that the significantly reduced emission of harmful pollutants can be attained, it pork belly meat is cooked by the Gas or electric pan instead of Charcoal-grill.

Chemical Constituents of Silene seulensis Nakai from Demilitarized Zone(DMZ)

  • Jung, Yeon Woo;Seo, Chan Gon;Lee, Ji Eun;Hong, Seong Su;Kwon, Jin Gwan;Shin, Hyun Tak;Jung, Su Young;Choi, Jeong Jun;Choi, Chun Whan;Kim, Jin Kyu
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2018.10a
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    • pp.92-92
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    • 2018
  • Silene seulensis Nakai was used as traditional medicines in Korea, we collected plant from demilitarized zone (DMZ). S. seulensis was extracted with 30, 50, and 70% ethanol and partitioned successively with n-hexane, EtOAc, dichloromethane and BuOH. These extracts (30, 50 and 70% ethanol) were evaluated the cytotoxicity on B16F10 and Hacat cell lines. The LC-MS/MS data of each fractions (n-hexane, EtOAc, dichloromethane, and BuOH) were compared with MS library, combined with ultraviolet/visual (UV/Vis) and MS data for faster determine structure by database search results. This led to the identification of four compounds (1-4) from S. seulensis. These compounds was isolated first time from S. seulensis. Their chemical structures are elucidated by combinations of NMR and mass spectrometry techniques.

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Quantitative Determination of Eleutheroside B and I from Acanthopanax Species by High Performance Liquid Chromatography

  • Kang, Jong-Seong;Linh, Pham-Tuan;Cai, Xing-Fu;Kim, Hang-Sup;Lee, Jung-Joon;Kim, Young-Ho
    • Archives of Pharmacal Research
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    • v.24 no.5
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    • pp.407-411
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    • 2001
  • Reversed-phase high performance liquid chromatographic method was applied for the determination of eleutheroside B and E in the various Acanthopanax species collected In Korea. The stationary phase used was Zorbax 300 SB $C_{18}$ and a mobile phase program was used, which started at 6% acetonitrile for 2 min, and then a linear gradient was operated for the next 18 min to 17% acetonitrile at a flow rate of 1.0 ml/min. The column effluent was monitored at UV 210 nm. Identification was carried out by comparing the retention time and the LC/MS spectrum of each peak corresponding to eleutheroside B and E from sample with those of standards. In general, the contents of eleutheroside B and 1 in stems were higher than those In roots. Acanthopanax species could be classified into two groups based upon the contents of eleutheroside B and E: one group contains no or very little eleutheroside B and another contains both eleutheroside B and E.

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Investigation on Bromate Formation and Removal of NOM during Ozonation in Super Ozone Mass Transfer Reactor (고효율 오존장치를 이용한 NOM 제거 및 Bromate 생성 특성)

  • Song, Ki-Ju;Choi, Il-Hwan;Baek, Kyoung-Hee;Lee, Sang-Tae
    • Journal of Korean Society on Water Environment
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    • v.22 no.6
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    • pp.1137-1143
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    • 2006
  • In this study we investigated the removal characteristics of NOM and bromate formation characteristics in SOMT reactor. The system was recently developed as a novel ozone reactor and installed in SJ pilot plant. DOC values were decreased within 3% after treatment of 0.5~2.0 mg/L ozone dosage in SOMT reactor while the $UV_{254}$ value was 69% decreased at 2.0 mg/L ozone dosage. The composition of NOM was analysed by LC-OCD (Organic Cabon Detector) after ozone treatment in SOMT reactor to elucidate the variation of NOM character. Polysaccharide (more than 20,000 g/mol) fraction of NOM was decomposed while building blocks (350~500 g/mol) and neutral (less than 350 g/mol) fraction increased. Spiked bromide reacted with 0.5~2.0 mg/L ozone dosage in the SOMT reactor. The bromate formation was proportional to the ozone dosage ($R^2=0.978$) but not proportional to reaction time. The maximum concentration of formated bromate was not exceeded to 10% of spiked bromide concentration.

Characteristics of the Purple Pigment Compound in Halophytic Plant, Suaeda japonica (내염성 식물 칠면초 (Suaeda japonica )가 갖는 자색 색소의 특징)

  • Chung, Sang-Ho
    • Proceedings of the Korea Contents Association Conference
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    • 2013.05a
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    • pp.361-362
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    • 2013
  • As one of the steps toward understanding how the plant is well adapted to strongly saline habitats, the purple pigment compound that is accumulated in Suaeda japonica was extracted and characterized. The extracted pigment compound exhibited typical characteristics of betacyanin that were represented by water solubility, pH- and temperature-dependent color changes, sensitivity to light, UV-Vis spectra, and gel electrophoretic migration pattern. LC-MS of the extracted pigment compound showed the presence of two major protonated molecular ions ($[M+H]^+$) at m/z 651.1 and m/z 827.1. According to the DPPH assay, it was found to have an antioxidant activity that is linearly increased in proportion to the reaction time for up to 30 min, and the activity was comparable to that of control BHA at 9.0 mg/ml. The cytotoxic activity against several tumor cell lines was also examined following the MTT assay. The significant growth inhibitory effect was observed on two tumor cell lines, SW-156 (human kidney carcinoma) and HEC-1B (human endometrial adenocarcinoma). Probably, the pigment compound may function as an osmolyte to uphold halotolerant physiological processes in saline environment.

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Simultaneous Determination of Sulfonamides in Porcine and Chicken Muscle Using High Performance Liquid Chromatography with Ultraviolet Detector

  • Shim, You-Sin;Shin, Dong-Bin;Cho, Yong-Sun;Choi, Yun-Hee;Lee, Sang-Hee
    • Food Science and Biotechnology
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    • v.18 no.6
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    • pp.1430-1434
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    • 2009
  • The present study used the liquid extraction pretreatment method and developed a liquid chromatographyultraviolet detector (LC-UV) for the simultaneous determination of 14 sulfonamides (SAs) residues in porcine and chicken muscle. Linearity within a range of $50-150\;{\mu}g/kg$ was obtained with the correlation coefficient ($r^2$) of 0.9673-0.9997. The mean recovery of SAs was 55.9-109.7% (relative standard deviations; RSDs 1.7-17.3%) in porcine muscle and 52.8-112.4% (RSDs 2.3-16.9%) in chicken muscle. The limits of detection (LODs) and limits of quantification (LOQs) were 2-32 and $7-96\;{\mu}g/kg$ in porcine muscle, and 4-32 and $13-97\;{\mu}g/kg$ in chicken muscle, respectively. These values were lower than the maximum residue limits (MRLs) established by the European Union. The sum of all SAs residues present should be less than $100\;{\mu}g/kg$.

EO Performances of Flexible TN-LCD using in-situ Ultraviolet Exposure during Imidization of Polyimide on the Polymer Film

  • Moon, Hyun-Chan;Hwang, Jeoung-Yeon;Lee, Whee-Won;Seo, Dae-Shik
    • Transactions on Electrical and Electronic Materials
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    • v.6 no.3
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    • pp.106-109
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    • 2005
  • We have investigated the generation of pretilt angle for a nematic liquid crystal (NLC) alignment with in-situ photoalignment method on polyimide (PI) surfaces using polymer films. Especially, we studied in-situ photoalignment changing heating temperature from $50^{\circ}C\;to\;120^{\circ}C$ on the polymer film. The LC aligning capabilities and pretilt angle on the polymer substrates were better than those on the glass substrate using in-situ photoalignment method. It is considered that this increase in pretilt angle may be attributed to the roughness of the micro-groove substrate induced by the in-situ photoalignment. As temperature of heated subtrate and UV exposure time increase, pretilt angle of the cell used polymer film increased. It is considered that the heating temperature of substrate is attributed to generate pretilt angle. Also, electro-optical performances of the in-situ photoaligned TN cell using the polymer substrate are almost the same as that of the TN cell using the glass substrate.

Study on Electro-optical Characteristics in the Optically Compensated Splay Cell using Polymer Surface Alignment (고분자 표면 배향을 이용한 광학 보상 퍼짐 셀의 특성 향상 연구)

  • Kim, Seong-Su;Hwang, Seong-Jin;Hwang, Seong-Han;Lee, Myong-Hoon;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.424-425
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    • 2007
  • We have studied the optically compensated splay mode using reactive mesogen (RM) monomer to reduce setting voltage and phase transition time from initial bend to splay state. When the OCS cell has low pretilt angle close to $45^{\circ}C$, OCS state can be formed easily. The low pretilt angle was formed through the polymerization of UV curable reactive RM monomer at the surfaces. In this way, reorientation of the LC is well defined and thus the device shows better performances in setting voltage and phase transition time.

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Features and Functions of Purple Pigment Compound in Halophytic Plant Suaeda japonica : Antioxidant/Anticancer Activities and Osmolyte Function in Halotolerance

  • Chung, Sang Ho
    • Korean Journal of Plant Resources
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    • v.31 no.4
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    • pp.342-354
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    • 2018
  • Suaeda japonica is a halophytic plant that lives in mudflat at intertidal zone of western and southern coastal areas of Korea. The seawater-living plants showed a purple color during their whole life. In contrast, freshwater-living plants displayed a green color in leaves. When seawater-living plants were transferred to potting soil, the purple color was gradually changed to green in the leaves. The extracted purple pigment compound exhibited typical characteristics of betacyanin that were represented by water solubility, pH- and temperature-dependent color changes, sensitivity to light, UV-Vis spectra, and gel electrophoretic migration pattern. The LC-MS analysis of the extracted pigment compound showed the presence of two major protonated molecular ions ($[M+H]^+$) at m/z 651.1 and m/z 827.1. Antioxidant activity of the pigment compound was determined using stable free radical DPPH assay. It was found to have an antioxidant activity that is linearly increased in proportion to the reaction time for up to 30 min, and the activity was comparable to that of control BHA at 9.0 mg/ml. The anticancer activity against several tumor cell lines was also examined following the MTT assay. The significant growth inhibitory effect was observed on two tumor cell lines, SW-156 (human kidney carcinoma) and HEC-1B (human endometrial adenocarcinoma). Probably, the pigment compound may function as an osmolyte to uphold halotolerant physiological processes in saline environment.