• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.8
• /
• pp.1194-1199
• /
• 2015

Vitamin $K_1$ (phylloquinone) content of commonly consumed foods in Korea were determined by solvent extraction followed by reversed-phase liquid chromatography using post-column derivatization and fluorescence detection. Samples were obtained in the years of 2013 and 2015. In this study, 46 vegetables, 14 fruits, and 6 legumes were analyzed. Relatively higher amounts of vitamin $K_1$ were found in sweet potato leaves, green kiwi, and mung beans among vegetables, fruits, and legumes, respectively. The content of vitamin $K_1$ in vegetables including spinach, broccoli, and potato ranged from non-detectable (ND) to $1,467.3{\mu}g/100g$. The content of vitamin $K_1$ in fruits ranged from ND to $42.7{\mu}g/100g$. The content of vitamin $K_1$ in legumes, including soybeans, mung beans and peas ranged from 1.7 to $63.4{\mu}g/100g$. In addition, the analytical method validation parameters including recovery, reproducibility, repeatability, peak purity, and linearity were calculated to ensure the method's validity. The results showed high linearity with a correlation coefficient of 0.9999. Overall recovery was close to 100% (n=5). This study revealed reliable vitamin K content in commonly consumed foods in Korea for a nutritional information and food composition database.

• Journal of Environmental Health Sciences
• /
• v.38 no.2
• /
• pp.105-117
• /
• 2012

Objectives: This study aimed to assess the concentration of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) in blood and factors controlling their exposure among Koreans. Methods: Study subjects were selected to include 718 members of the general population residing in five metropolitan cities and the Gangwon Province area from August 2008 to January 2009. A questionnaire was administered to investigate lifestyle, socio-demographic characteristics, and other related factors. Blood samples were collected and extracted using solid-phase extraction and anion-exchange methods, and quantified by high-performance liquid chromatograph (HPLC, Agilent 1200 Series) coupled with a Triple Quad LC-MS/MS system (Agilent 6410). Results: Geometric mean concentrations of PFOA and PFOS in the blood were measured as 1.82 and 6.06 ng/ml, respectively. Mean PFOA and PFOS concentrations generally increased with age in both genders. Blood PFOA concentration was significantly different according to such variables as age, family income, residential district, and province. Blood PFOS concentration was significantly different by such variables as gender, age, lifestyle factors such as regular exercise, alcohol consumption, and smoking status. Also, family income, hazardous facilities, job classification, and province contributed significantly to differences in blood PFOS concentration levels. Conclusions: Blood PFOA and PFOS concentrations in Koreans were similar with those found in Japan, the USA, and Germany, but less than those in Australia. PFOA and PFOS exposure seems to be affected by a variety of factors in Korea. Therefore, investigation is required for each factor to assess the relative contribution of different variables.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2009.11a
• /
• pp.278-278
• /
• 2009

A photovoltaic device consisting of arrays of radial p-n junction wires enables a decoupling of the requirements for light absorption and carrier extraction into orthogonal spatial directions. Each individual p-n junction wire in the cell is long in the direction of incident light, allowing for effective light absorption, but thin in orthogonal direction, allowing for effective carrier collection. To fabricate radial p-n junction solar cells, p or n-type vertical Si wire cores need to be produced. The majority of Si wires are produced by the vapor-liquid-solid (VLS) method. But contamination of the Si wires by metallic impurities such as Au, which is used for metal catalyst in the VLS technique, results in reduction of conversion efficiency of solar cells. To overcome impurity issue, top-down methods like noble metal catalytic etching is an excellent candidate. We used noble metal catalytic etching methods to make Si wire arrays. The used noble metal is two; Au and Pt. The method is noble metal deposition on photolithographycally defined Si surface by sputtering and then etching in various BOE and $H_2O_2$ solutions. The Si substrates were p-type ($10{\sim}20ohm{\cdot}cm$). The areas that noble metal was not deposited due to photo resist covering were not etched in noble metal catalytic etching. The Si wires of several tens of ${\mu}m$ in height were formed in uncovered areas by photo resist. The side surface of Si wires was very rough. When the distance of Si wires is longer than diameter of that Si nanowires are formed between Si wires. Theses Si nanowires can be removed by immersing the specimen in KOH solution. The optimum noble metal thickness exists for Si wires fabrication. The thicker or the thinner noble metal than the optimum thickness could not show well defined Si wire arrays. The solution composition observed in the highest etching rate was BOE(16.3ml)/$H_2O_2$(0.44M) in Au assisted chemical etching method. The morphology difference was compared between Au and Pt metal assisted chemical etching. The efficiencies of radial p-n junction solar Cells made of the Si wire arrays were also measured.

• Journal of Environmental Health Sciences
• /
• v.46 no.3
• /
• pp.324-334
• /
• 2020

Objectives: This study was conducted to estimate the related health risk by investigating the content of biogenic amines (BAs) in commercial fermented alcoholic beverages. Methods: Ninety-seven samples, including takjus (34), fruit wines (26), distilled liquors (20) and beers (17) were purchased in Gangwon-do (Province) in 2019. The eight BAs (putrescine, cadaverine, spermine, spermidine, tyramine, β-phenylethylamine, histamine, and tryptamine) were analyzed by high performance liquid chromatograph (HPLC) after extraction (0.4 M HClO₄), pigment removal (carbon cartridge) and derivatization (1% dansylchloride). The health risk of exposure to BAs due to ingestion of commercial fermented alcoholic beverages was estimated as the margin of exposure (MOE). Results: Various BAs were detected in takju, fruit wine, distilled liquor and beer. Putrescine (not detected (ND)-12.60 mg/L), cadaverine (ND-5.45 mg/L), tyramine (ND-8.34 mg/L), β-phenylethylamine (ND-13.73 mg/L), histamine (ND-7.96 mg/L), and tryptamine (ND-19.00 mg/L) were found in takju. Putrescine (ND-15.34 mg/L), cadaverine (ND-7.90 mg/L), β-phenylethylamine (ND-3.06 mg/L), histamine (ND-9.68 mg/L), and tryptamine (ND-14.06 mg/L) were identified in fruit wine. Putrescine (less than limit of detection (

• Journal of Korean Society on Water Environment
• /
• v.34 no.1
• /
• pp.46-56
• /
• 2018

A mcyB-specific Ultra-Rapid quantitative PCR was developed for the quantitative detection of Microcystis aeruginosa, which is often a dominant species in green tide. McyB-specific UR-qPCR was optimized under extremely short times of each step in thermal cycles, based on the specific primers deduced from the mcyB in microcystin synthetase of M. aeruginosa. The M. aeruginosa strain KG07 was used as a standard for quantification, after the microscopic counting and calculation by mcyB-specific UR-qPCR. The water samples from the river water with the Microcystis outbreak were also measured by using both methods. The $1.0{\times}10^8$ molecules of mcyB-specific DNA was recognized inner 4 minutes after beginning of UR-qPCR, while $1.0{\times}10^4$ molecules of mcyB-specific templates was detected inner 7 minutes with quantitative manner. From the range of $1.0{\times}10^2$ to $1.0{\times}10^8$ initial molecules, quantification was well established based on $C_T$ using mcyB-specific UR-qPCR (Regression coefficiency, $R^2=0.9977$). Between the numbers of M. aeruginosa cell counting under microscope and calculated numbers using mcyB-specific UR-qPCR, some differences were often found. The reasons for these differences were discussed; therefore, easy compensation method was proposed that was dependent on the numbers of the cell counting. Additionally, to easily extract the genomic DNA (gDNA) from the samples, a freeze-fracturing of water-sample using liquid nitrogen was tested, by excluding the conventional gDNA extraction method. It was also verified that there were no significant differences using the UR-qPCR with both gDNAs. In conclusion, the mcyB-specific UR-qPCR that we proposed would be expected to be a useful tool for rapid quantification and easy monitoring of M. aeruginosa in environmental water.

• Journal of Life Science
• /
• v.28 no.8
• /
• pp.917-922
• /
• 2018

Centella asiatica is one of the local herbs that is claimed to possess various physiological effects. C. asiatica also accumulates large amounts of pentacyclic triterpenoid saponins known as centelloids. These terpenoids usually include asiatic acid, asiaticoside, madecassoside, and madecassic acids. In the present study, to understand the changes of triterpene glycoside levels in the different shoot tissues of C. asiatica during seasonal cultivation, we investigated the High-Performance Liquid Chromatography (HPLC) analysis via different extraction methods, such as water, 20% ethanol and methanol extracts. Significant increases were observed in the levels of madecassoside and asiaticoside in the leaf extracts by methanol compare with extracts using water or 20% ethanol. Additionally, we also analyzed the various antioxidant activity in the different shoot tissues of C. asiatica using different extracts, such as leaves, petioles and both materials. Among these petiole extracts showed high 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTs) scavenging activity in all extracts, whereas 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity exhibited high activity levels in the leaf part using methanol and ethanol extracts. Levels of total phenolics and flavonoid also showed the highest levels in the leaf tissues using all extracts such as methanol, ethanol and water. Our results indicated that the increased levels of triterpene glycoside and antioxidant activity in the leaf parts of the C. asiatica were indicating that useful metabolites were mainly maintained through seasonal cultivation such as madecassoside, asiaticoside.

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.9
• /
• pp.825-830
• /
• 2009

Pharmaceutical compounds enter the water environment through the diverse pathways. Because their concentration in the water environment was frequently detected in the level of ppt to ppb, the monitoring system should be optimized as much as possible for finding appropriate management policies and technical solutions. One Factor At a Time (OFAT) approach approximating the response with a single variable has been preferred for the optimization of LC-MS/MS operational conditions. However, it is common that variables in analytical instruments are interdependent. Therefore, the best condition could be found by using the statistical optimization method changing multiple variables at a time. In this research, response surface analysis (RSA) was applied to the LC-MS/MS analysis of emerging antibiotic compound, sulfamethoxazole, for the best sensitivity. In the screening test, fragmentation energy and collision voltage were selected as independent variables. They were changed simultaneously for the statistical optimization and a polynomial equation was fit to the data set. The correlation coefficient, $R^2$ valuerepresented 0.9947 and the error between the predicted and observed value showed only 3.41% at the random condition, fragmentation energy of 60 and collision voltage of 17 eV. Therefore, it was concluded that the model derived by RSA successfully predict the response. The optimal conditions identified by the model were fragmentation energy of 116.6 and collision voltage of 10.9 eV. This RSA can be extensively utilized for optimizing conditions of solid-phase extraction and liquid chromatography.

• Journal of Life Science
• /
• v.18 no.7
• /
• pp.958-962
• /
• 2008

To get the nutritional data of hot water extract from imported kangaroo tails, research was done about contents of collagen, chondroitin sulfate, protein, fat, mineral ions, and conjugated linoleic acid (CLA) in tails. Collagen content of sulfuric acid digested sample was way higher at bones than meats in both kangaroo tail and cow tail. Comparing kangaroo tail and cow tail, meat of kangaroo tail have 1.7 times higher collagen content than that of cow tail. Content of collagen in bone parts of kangaroo tail was also higher 1.2 times than that of cow tail. Meat sample of kangaroo tail (liquid extraction) have 1.3 times higher content of muco-polysaccharide than that of cow tail. In the born part, kangaroo tail was 2.4 times higher than cow tail in its content of muco-polysaccharide. The CLA content of the kangaroo tail showed the content that was higher than 0.9% of the cow tail for 4.9% and showed about 5.3 times high ratios. Especially in kangaroo tail, a band with high content of CLA was found between C18:1 and C18:2.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.10 no.1
• /
• pp.103-106
• /
• 1981

A strain of Staphylococcus aureus resistant against cadmium was cultivated by using a liquid medium containing 10ppm cadmium ion, and then, it was fractionated into several fractions as described in the previous paper. Content of the metal in each fraction was determined through an atomic absorption spectrometery. The results are as follows; (1) A $690.9{\mu}g$ cadmium was contained in one gram dry cell. (2) A 39.9% of total cadmium was easily extracted by TCA, however a 52.2% was unextractable even by series of extraction with TCA, ethanol-ehter, perchloric acid and ammonium water. (3) Among the fractions prepared along the cellular structure, plasma membrane fraction showed a highest content of the metal by containing a 59.1%. (4) The fraction of cytoplasm and cell wall contained a 26.8 and 14.1%, respectively. (5) More than 90% of the metal contained in the cell wall was detected from the fraction of lipopolysaccharide. It is considered from these results tht at least a 70% of the cadmium up taken by the resistant cell associates with membranous structure in the cell surface.

• Journal of Life Science
• /
• v.16 no.2 s.75
• /
• pp.328-332
• /
• 2006

The possible presence of inhibitors of pancreatic lipase (tricaylglycerol acylhydrolase EC 3.1.1.3) was screened from Korean traditional edible or medicinal herbs. Among tested herbs, Arecae pericarpium, Mucunae Caulis, Rhus javanica, Thujae orientalis were shown to have strong inhibitory effect against pancreatic lipase. Thujae orientalis was finally selected as a candidate for pancreatic lipase inhibitor. The extract of Thujae orientalis was showed selective inhibition on porcine pancreatic lipase activity. Active inhibitors, TF-1, TF-2, TF-3, were purified from an extract of Thujae orientalis, using chloroform extraction, followed by successive chromatography in silica gel and LH-20 and high performance liquid chromatography (HPLC). The $IC_{50}$ values of TF-1, TF-2, TF-3 and orlistat were 44.7, 98.7, 46.1 and $27.6{\mu}g/ml$, respectively. And also the TF-2 and orlistat were shown to be inhibitory effect on the differentiation of preadipocyte NIH-3T3 L1 cells at a concentration of $10{\mu}g/ml$.