• Title/Summary/Keyword: Micro-HPLC

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Discrimination of Ginseng Habitat by Using Instrumental Analysis Techniques

  • Sohn H. J.;Lee S. K.;Cho B. G.;Kim S. J.;Lee N. Y.;Choi D. S.;Jeong M. S.;Bae H. R.;Yang J. W.
    • Proceedings of the Ginseng society Conference
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    • 2002.10a
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    • pp.238-252
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    • 2002
  • In order to screen out indicators for the discrimination of ginseng habitat, some physical and chemical characteristics of Korean red ginsengs (94 kinds) and Chinese red ginsengs (50 kinds) were analyzed by using a rheometer, an electronic nose system, a combined technique of solid phase micro-extraction (SPME) and gas chromatograph equipped with an electron capture detector (GC/ECD), an X-ray fluorescence spectrometer (XRF), an inductively coupled plasma mass spectrometer (ICP/MS), a near infrared spectrometer (NIRs) and high performance liquid chromatography equipped with evaporative light scattering detector (HPLC/ELSD). The results are summarized as follows: (i) The rhizome strengths of Korean red ginsengs were significantly higher than those of Chinese red ginsengs. (ii) The electronic nose patterns of Korean red ginsengs were significantly different from those of Chinese red ginsengs. (iii) Some unidentified peaks were detected not in the headspace of Korean red ginsengs but in the headspace of Chinese red ginsengs when the headspace volatiles prepared by the SPME technique were analyzed by GC/ECD. (iv) Either the content ratios of K to Ca or Mn to Fe were significantly different between Korean red ginsengs and Chinese red ginsengs. (v) The reflectance ratios of NIRs wavenumbers such as $904\;cm^{-1}\;to\;1088\;cm^{-1}$ for Korean red ginsengs were significantly different from those for Chinese red ginsengs. (vi) The content ratios of ginsenoside-Rg to ginsenoside-Re of Korean red ginsengs were significantly higher than those of Chinese red ginsengs. These results indicate that the rhizome strength, the electronic nose pattern, the occurrence of ECD-sensitive headspace volatile components, the content ratios of K to Ca and Mn to Fe, the NIRs pattern and the content ratio of ginsenoside-Rg to -Re may be indicators for the discrimination of ginseng habitat.

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Genotoxicity Evaluation of Capsaicin-Containing (CP) Pharmacopuncture, in an In Vivo Micronucleus Test

  • Hwang, Ji Hye;Ku, Jaseung;Jung, Chul
    • Journal of Pharmacopuncture
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    • v.23 no.4
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    • pp.237-246
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    • 2020
  • Objectives: Capsaicin-containing (CP) pharmacopuncture was developed to treat neuropathic pain. This study was conducted to assess the toxicity of CP extract for pharmacopuncture, using a micronucleus test. Methods: First, a dose range finding study was conducted. Then an in vivo micronucleus test was performed to determine the induction of micronuclei in mouse bone marrow cells after intramuscular administration of CP twice with a 24-hour interval to 8-week-old ICR mice. A high dose of 0.2 mL/animal was selected, and this was sequentially diluted by applying a geometric ratio of 2 to produce two lower dose levels (0.1 and 0.05 mL/animal). In addition, negative and positive control groups were set up, and an HPLC analysis was conducted to confirm the capsaicin content of CP. Results: The incidence of micro-nucleated polychromatic erythrocytes in polychromatic erythrocytes in the CP-treated group was similar to that in the negative-control group, while that in the positive-control group was significantly greater. In addition, the ratio of polychromatic erythrocytes to total erythrocytes in the CP treatment group and the positive control group was not significantly different from the negative control group. In the HPLC analysis, capsaicin in the CP was identified through a comparison with the retention time of the capsaicin standard of 27 min. Conclusion: CP did not show any indication of any potential to induce micronuclei formation in bone marrow cells of ICR mice under the conditions of this study. Further toxicity studies are necessary to ensure the safety of the use of CP in clinical practice.

An analytical method of heterocyclic amines by LC/MS (LC/MS를 이용한 heterocyclic amines의 분석법)

  • Myung, Seung-Woon
    • Analytical Science and Technology
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    • v.20 no.2
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    • pp.115-123
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    • 2007
  • The heterocyclic amines (HAs) are a family of mutagenic/carcinogenic chemicals formed from the cooking of muscle meats such as beef, meat, fowl, and fish. A major draw back in the analysis of HAs from foods is their very low level of concentration (ng/g) and a number of matrix interferences in samples. Solid-phase extraction (SPE) is one of the procedures widely used for the extraction and purification of HAs in food samples. In this study, several SPE procedures of HAs determination were performed. Recoveries of the HAs were obtained from comparing a matrix such as a standard methanolic solution and pre-cooked meat extracts. Recovery values were ranging between 25.3 and 93.0 % at a concentration of 25.0 ng/g. HAs were determined with high sensitivity by micro-HPLC (${\mu}$-HPLC) analysis with electrospray ionization mass spectrometry (ESI-MS). Another developed method, which is freezing filtration method, shows better extraction recoveries and good precisions. The established method will be applicable to monitoring of heterocyclic amines from the cooked meat.

Study of Nano-scale Fullerene (C60) Clusters Formed in Micro-sized Droplet by UV Irradiation

  • Yeo, Seung-Jun;Ahn, Jeung-Sun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.571-571
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    • 2012
  • We discovered the formation of C60 aggregates in solution by means of photoluminescence spectroscopic study on C60 in solutions. From the in-depth investigation of temperature dependence of the luminescence of C60 in toluene, benzene and CS2 solutions, we reported that the C60 aggregates are formed during cooling at the freezing temperature of these solvents. Furthermore, the C60 aggregates can be changed to stable structures by irradiating with UV pulse-laser (Nd:YAG laser, 355nm). As a consequence, we could obtain nano-scale photo-polymerized C60 clusters, which appear as round-shaped nano- scale particles in high resolution transmission electron-microscopy (HRTEM) images. However, the yield of the nano-scale C60 clusters obtained by this method is too small. So we designed and developed a system to obtain C60 cluster of macroscopic quantity by using ultrasonic nebulizer. In this system, C60 solution was vaporized to several micro-sized droplets in vacuum, resulting in the formation of C60 aggregates by evaporating solvent (toluene). The system was invented to produce nano-scale carbon clusters by the irradiation of UV light upon C60 aggregates in vacuum. We have characterized the products, C60 cluster, obtained from the system by using UV absorption spectra and HPLC spectra. Although the products have a possibility of inclusion various forms of C60 cluster, results support that the product formed from the system by using vaporizer method establishes a new method to obtain C60 cluster in macroscopic quantity. In the presentation, the details of the system and the results of characterization are reported.

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Synthesis of 18F-labeled Novel Phosphonium cations as PET Myocardial Perfusion Imaging Agents: Pilot Imaging Studies

  • Ayoung Pyo;Jung-Joon Min;Dong-Yeon Kim
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.8 no.2
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    • pp.63-70
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    • 2022
  • The development of myocardial perfusion imaging (MPI) agents has been motivated because coronary artery disease has been one of the leading causes of death worldwide since the 1960s. Several positron emission tomography (PET) MPI agents were developed, and 18F-labeled phosphonium cations were reported actively among them. In this study, we synthesized novel 18F-labeled phosphonium cations, (5-[18F]fluoropentyl)diphenyl(pyridin-2-yl)phosphonium and (2-(2-[18F]fluoroethoxy)ethyl)diphenyl(pyridin-2-yl)phosphonium, and evaluated potential as MPI agents. Two labeled compounds were synthesized via nucleophilic substitution reactions of 18F-fluoride with the appropriate tosylate precursor in the presence of Kryptofix 2.2.2 and K2CO3. MicroPET studies were performed in normal rats to evaluate in vivo distribution of radiolabeled phosphonium cations for 60 min. The radiolabeled compounds were synthesized with 5%-10% yield. The radiochemical purity of labeled compounds was > 98% by analytical HPLC, and the specific activity was > 11.8 GBq/µmol. The result of microPET studies of these labeled compounds in rats showed intense uptake in the myocardium at 30 and 60 min. The results suggest that these 18F-labeled novel phosphonium cations would have potential as promising candidates for myocardial perfusion imaging.

A Novel Chlorophyll d-containing Organism: Discovery and its Significance

  • Murakami, Akio;Kawai, Hiroshi;Adachi, Kyoko;Sakawa, Takahiro;Miyashita, Hideaki;Mimuro, Mamoru
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.74-77
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    • 2002
  • Chlorophyll (Chi) d was assigned to an antenna pigment of red algae in 1943, but its presence and function in red algae have not been necessarily clear for a long time. In 1996, it was shown that Chi d functioned as a major antenna pigment in a peculiar oxygenic photosynthetic prokaryote, Acaryochloris marina, isolated as a symbiont of a colonial ascidian from coral reefs. This finding evoked the necessity for reexamination of the presence and function of Chi d in red algae. We found Chi d in methanol-extract from several marine red algae, and the relative content was high in one species, Ahnfeltiopsis flabelliformis. Absorption and fluorescence spectra, HPLC analysis, and NMR and mass spectroscopy characterized Chi d extracted from the red algal thalli, and those were essentially identical to those of Chi d isolated from A. marina. However, micro-spectrophotometric analysis suggested that Chi d was not an actual constituent of the red algae but came from epiphyte(s) attached to surface of red algal thalli.

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Gastrointestinal Absorption of Phenytoin from on Oil-in-water Microemulsion

  • Kwon, Kwang-Il;Bourne, David-W.A.
    • Archives of Pharmacal Research
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    • v.20 no.5
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    • pp.480-485
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    • 1997
  • The absorption profile of phenytoin Na emulsion were examined compared to that of phenytoin suspension after oral administration in the rat. The corn oil-in-water emulsion, particle size of $184{\pm}$57.8 nm, was prepared using a microfludizer, and phenytoin Na added by shaft homogenizer. The phenytoin emulsion or suspension, 100 mg/kg, were intubated intragastrically using oral dosing needle and blood samples were withdrawn via an indwelling cannula from the conscious rat. Plasma concentrations of phenytoin were measured with HPLC using phenacetin as an internal standard. The plasma concentration versus time data were fitted to a one compartment open model and the pharmacokinetic parameters were calculated using the computer program, Boomer. The phenytoin plasma concentrations from the emulsion at each observed time were about 1.5-2 times higher than those from the suspension, significantly at time of 5, 6 and 7 hr after administration. The absorption $(k_a)$ and elimination rate constant $(k_e)$ were not altered significantly, however the AUC increased from 65.6 to $106.7{\mu}ghr/ml$ after phenytoin suspension or emulsion oral administration, respectively. From an equilibrium dialysis study, the diffusion rate constant $(k_{IE})$ was considerably higher from the phenytoin Na emulsion $(0.0439 hr{-1})$ than phenytoin suspension $(0.0014 hr{-1})$.

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Monthly HPLC Measurements of Pigments from an Intertidal Sediment of Geunso Bay Highlighting Variations of Biomass, Community Composition and Photo-physiology of Microphytobenthos (HPLC를 이용한 근소만 조간대 퇴적물내의 저서미세조류 현존량, 군집 및 광생리의 월 변화 분석)

  • KIM, EUN YOUNG;AN, SUNG MIN;CHOI, DONG HAN;LEE, HOWON;NOH, JAE HOON
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.24 no.1
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    • pp.1-17
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    • 2019
  • In this study, the surveys were carried out from October (2016) to October (2017) along the tidal flat of Geunso Bay, Taean Peninsula of the western edge of Korea. The sampling trips were carried out for a total of 16 times, once or twice a month. In order to investigate the monthly variation of the microphytobenthos (MPB) biomass, community composition and photo-physiology were analyzed by HPLC (High performance liquid chromatography). The total chlorophyll a (TChl a) concentrations used as an indicator of biomass of MPB in the upper 1 cm sediment layer ranged from 40.4 to $218.9mg\;m^{-2}$ throughout the sampling period. TChl a concentrations showed the maximum level on $24^{th}$ of February and remained high throughout March after which it started to declined. The biomass of MPB showed high values in winter and low values in summer. The monthly variations of Phaeophorbide a concentrations suggested that the low grazing intensity of the predator in the winter may have partly attributed to the MPB winter blooming. As a result of monthly variations of the MPB community composition using the major marker pigments, the concentrations of fucoxanthin, the marker pigment of benthic diatoms, were the highest throughout the year. The concentrations of most of the marker pigments except for chlorophyll b (chlorophytes) and peridinin (dinoflagellates) increased in winter. However, the concentrations of fucoxanthin increased the highest, and the relative ratios of the major marker pigments to TChl a except fucoxanthin decreased during the same period. The vertical distribution of Chl a and oxygen concentrations in the sediments using a fluorometer and an oxygen micro-optode Chl a concentrations decreased with oxygen concentrations with increasing depth of the sediment layers. Moreover, this tendency became more apparent in winter. The Chl a was uniformly vertical down to 12 mm from May to July, but the oxygen concentration distribution in May decreased sharply below 1 mm. The increase in phaeophorbide a concentration observed at this time is likely to be caused by increased oxygen consumption of zoobenthic grazing activities. This could be presumed that MPB cells are transported downward by bioturbation of zoobenthos. The relative ratios (DT/(DD+DT)) obtained with diadinoxanthin (DD) and diatoxanthin (DT), which are often used as indicators of photo-adaptation of MPB, decreased from October to March and increased in May. This indicated that there were monthly differences in activity of Xanthophyll cycle as well.

Preparation and Release Behavior of Ipriflavone-Loaded PLGA Microsphere for Tissue Engineered Bone (이프리플라본을 함유한 생분해성 PLGA 미립구의 제조 및 조직공학적 골재생을 위한 영향평가)

  • So, Jung-Won;Jang, Ji-Wook;Kim, Soon-Hee;Kim, Geun-Ah;Choi, Jin-Hee;Rhee, John-M.;Son, Young-Suk;Min, Byoung-Hyun;Khang, Gil-Son
    • Polymer(Korea)
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    • v.33 no.1
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    • pp.26-32
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    • 2009
  • The aim of this research was to prepare microparticulate systems based on poly (lactide-co-glycolide)(PLGA) for the local release of ipriflavone in order to reduce bone loss. We developed the IP loaded PLGA microspheres using relatively simple oil-in-water(O/W) solvent evaporation method. HPLC was used to perform the in vitro release test of IP and morphology of cell attached on the micro-spheres was investigated using SEM. Cytotoxicity was assayed by cell counting kit-8 (CCK-8) test. Osteogenic differential cells were analyzed by ALP activity. Through RT-PCR analysis, we observed osteocalcin, ALP, and Type I collagen mRNA expression. The release of IP in vitro was more prolonged over 42 days and IP/PLGA microspheres showed the improvement on the cell proliferation, ALP activity and RT-PCR comparing with control (only PLGA). This initial research will be used to direct future work involved in developing this composite injectable bone tissue engineering system.

Photosynthetic Characteristics of Benthic Microalgae Measured by HPLC and Diving Pulse Amplitude Modulated (PAM) Fluorometry on the Nakdong River Estuary of the Korean Peninsula (HPLC 및 Diving-PAM을 이용한 낙동강 하구 저서미세조류의 광합성 특성)

  • Jeong Bae Kim;Mi Hee Chung;Jung-Im Park
    • Korean Journal of Ecology and Environment
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    • v.57 no.2
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    • pp.61-74
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    • 2024
  • Daemadeung, located in the estuary of the Nakdong River, is formed by sand dunes and possesses well-developed intertidal flats. This study aimed to investigate the habitat of benthic microalgae, photosynthetic pigments, and photosynthetic efficiency in the intertidal flats of Daemadeung from January to December 2011. The inorganic nitrogen content in the sediment pore water was primarily composed of ammonium, while nitrate + nitrite was dominant in the upper layer water. The concentration of chlorophyll a and fucoxanthin in the sediment surface was significantly higher than the mean of all the sediment layer. The average Fv/Fm of benthic microalgae during the entire survey period was 0.52±0.03, with the highest value (0.61±0.08) observed in February. The rETRmax showed a seasonal trend, being high from spring to early autumn (April to October) and low from winter to early spring (January to March, November, December), with the highest value (153.05±2.30 µmol electrons m-2 s-1) in July and the lowest (38.49±5.17 µmol electrons m-2 s-1) in January. The average Fv/Fm of diurnal microalgae was 0.48±0.03, with the highest value (0.61±0.08) observed at noon. The rETRmax showed a highest peak at noon (54.24±11.35 µmol electrons m-2 s-1) and reached its lowest point at 16:00 (26.17±4.75 µmol electrons m-2 s-1). These findings suggest that the productivity of benthic microalgae varies significantly depending on the survey time and sediment depth. Therefore, to quantify the productivity of benthic microalgae using Diving-PAM, surveys should be conducted based on tidal conditions, and simultaneous pigment analysis of sediment layers should also be performed.