• Journal of Ginseng Research
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• v.42 no.2
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• pp.149-157
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• 2018

Background: Panax notoginseng leaves (PNL) exhibit extensive activities, but few analytical methods have been established to exclusively determine the dammarane triterpene saponins in PNL. Methods: Ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC/Q-TOF MS) and HPLC-UV methods were developed for the qualitative and quantitative analysis of ginsenosides in PNL, respectively. Results: Extraction conditions, including solvents and extraction methods, were optimized, which showed that ginsenosides Rc and Rb3, the main components of PNL, are transformed to notoginsenosides Fe and Fd, respectively, in the presence of water, by removing a glucose residue from position C-3 via possible enzymatic hydrolysis. A total of 57 saponins were identified in the methanolic extract of PNL by UPLC/Q-TOF MS. Among them, 19 components were unambiguously characterized by their reference substances. Additionally, seven saponins of PNL-ginsenosides Rb1, Rc, Rb2, and Rb3, and notoginsenosides Fc, Fe, and Fd-were quantified using the HPLC-UV method after extraction with methanol. The separation of analytes, particularly the separation of notoginsenoside Fc and ginsenoside Rc, was achieved on a Zorbax ODS C8 column at a temperature of $35^{\circ}C$. This developed HPLC-UV method provides an adequate linearity ($r^2$ > 0.999), repeatability (relative standard deviation, RSD < 2.98%), and inter- and intraday variations (RSD < 4.40%) with recovery (98.7-106.1%) of seven saponins concerned. This validated method was also conducted to determine seven components in 10 batches of PNL. Conclusion: These findings are beneficial to the quality control of PNL and its relevant products.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.577-588
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• 1995

The chemical constituents for the seawater and sediment were measured to evaluate pollution in the sea around Pusan Harbor in winter, n992. The average value of trophic state index (TSI) was 19.4 at the outside of Buk Harbor, 50,4 at the inside of Buk Harbor, 56,3 at the Nam Harbor and 5,0 at the Kamchun Harbor. The high correlation found in salinity-nutrients diagram with AOU suggested that the enrichment of nutrients in Pusan Harbor during winter was mainly due to the influx of terrestrial effluents and partially by regenerated nutrients from suspended organic matters in the water column. The mean values of total ignition loss (TIL), COD and total sulfide in the surface sediments were$12.1\%$, 17.5 mg/g.dry wt. and 1.18 mg/g.dry wt. respectively. The highest level of those parameters was shown mostly at the inside of Buk Harbor. The mean concentration of total organic carbon (TOC), total organic nitrogen (TON), and total phosphorus were 24.9 mg/g.dry wt., 1.3mg/g.dry wt. and 0.69 mg/g. dry wt., respectively, Both of the highest level for TOC and total phosphorus have found at the Nam Harbor. On the other hand, the Highest level for TON was found at the inside of Buk Harbor. The TOC/TON atomic ratio with a range of 10.2-60.2 (mean value of 22.5) strongly indicated the active role of the input from the terrestrial organic pollutants.

• Korean Journal of Ichthyology
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• v.7 no.1
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• pp.64-70
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• 1995

Vertical distribution of eggs and larvae of Maurolicus muelleri were studied in the south-eastern waters of Korea during 1985 and 1986. Samples were collected vertically at three different layers, 0~30 m, 30~50m and 50~100m. The densities of egg and larva were high in August. Eggs and zooplankton were abundant around the thermocline in the temperature range of $10{\sim}15^{\circ}C$ at the layers of 50 m depth in 1985, and 30~100m depth in 1986. Eggs in the cleavage stage were abundant at the layer of 50~100m depth, while those of processing embryonic body formation were tended to concentrate at the layer of 30~50m depth. The vertical distribution of each developmental stage differed according to sampling time. They were distributed uniformly at water column from 30 m to 100m depth in the midnight, but concentrated at the layer from 30 m to 50 m from dawn to sunset. Before and after midnight, eggs in the cleavage stage were most abundant. It was assumed that M. muelleri spawned at the layer of 50~100m depth around the midnight, and the eggs ascended to the layer of 30~50m depth with development.

• Journal of the Korea Concrete Institute
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• v.21 no.4
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• pp.465-471
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• 2009

To prevent the explosive spalling of the high strength concrete and control the rise of temperature in the steel rebar during fire, a fiber cocktail method has been proposed simultaneously with the use of polypropylene and steel fiber. After applying the fiber cocktail (polypropylene and steel fibers) into the mixture of high strength concrete with a compressive strength of between 40 and 100 MPa and evaluating the thermal properties at elevated temperatures, the fire test was carried out on structural members in order to evaluate the fire resistance performance. Two column specimens were exposed to the fire without loading for 180 minutes based on the standard curve of ISO-834. No explosive spalling has been observed and the original color of specimen surface was changed to light pinkish grey. The inner temperature of concrete dropped rapidly starting from 60mm deep. After 60 minutes of exposure to the fire, the temperature gradient of fiber cocktail reinforced high strength concrete was measured as 2.2oC/mm, which is approximately 5 times less than that of normal concrete. The final temperatures of steel rebar after 180 minutes of fire test resulted in 488.0oC for corner rebar, 350.9oC for center rebar, and 419.5oC for total mean of steel rebar. The difference of mean temperature between corner and center rebar was 137.1oC The tendency of temperature rise in concrete and steel rebar changed between 100oC and 150oC The cause of decrease in temperature rise was due to the water vaporization in concrete, the lower temperature gradient of the concrete with steel and polypropylene fiber cocktails, the moisture movement toward steel rebars and the moisture clogging.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.891-894
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• 2008

This study was performed to investigate how to design, where to construct, why to degrade, what plan to use systematically the underground structures such as underpass, underground passageways. About 50% of the underground structures are located on Seoul, Kyungi-Do. In design of the underground structures such as underpass, underground passageways, the required conditions are defined. And also in construction stage, the conditions of soil, required structure depth, site characteristics, reasonable construction method, are investigated. In the selection of details for underground structure, the items mainly considered, are the wall and column type, the sidewalk type, anchoring-system type, the water-proofing method, entranc shape. The reason and the adequate measures for the degradation of concrete structure are also investigated. The initial cracking properties due to the thermal characteristic are considered. The state of the art report on the new technologies are reviewed. The recent project for the systematically application to the underground structures is reviewed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1363-1368
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• 2008

The extraction and quantitative analysis conditions for astaxanthin from Haematococcus pluvialis, and the structural characteristics of H. pluvialis extract, H. pluvialis hydrolysate and synthetic astaxanthin were investigated using UV/visible and FT-IR spectrometers. Astaxanthin was dissolved in methanol, and then treated to enhance the solubility by sonication for 45 min. With sonication pretreatment, the solubility of astaxanthin increased up to 1.5 times compared to that without sonication. The extracts were hydrolyzed by cholesterol esterase for the analysis of H. pluvialis extract containing astaxanthin ester. A HPLC method using reverse phase C18 column with methanol-water (95:5, v/v) as mobile phase was developed to analyze astaxanthin. After hydrolysis, the absorption spectrum of H. pluvialis hydrolysat was changed to similar pattern to synthetic astaxanthin, confirming the extraction and analysis condition of astaxanthin from H. pluvialis.

• Korean Chemical Engineering Research
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• v.44 no.5
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• pp.453-459
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• 2006

D-tryptophan and N-CBZ-D-phenylalanine were separated using ionic liquid as additives for the mobile phase in high performance liquid chromatography (HPLC). The ionic liquid of 1-butyl-3- methylimidazolium tetrafluoroborate (${[BMIm]}^+{[BF_4]}^-$) was used. Mobile phases were 65％, 70％, and 80％ methanol in water with addition of different concentrations (0.5, 1.0, 1.5, 2.0, 4.0, 6.0, 8.0, 10.0, 12.0, and 15.0 mmol/L) of the ionic liquid. The experiments were performed on stainless steel column, $3.9{\times}300mm$ i.d., packed with $15{\mu}m$ octadecyl-bonded silica gel at laboratory.The retention factor of D-tryptophan was not negligibly changed while that of N-CBZ-D-phenylalanine was decreased. The resolution between the two components were affected by the contents of methanol and ionic liquid in the mobile phase. With the small content of methanol and the high concentration of ionic liquid, the resolution was improved.

• Journal of the Korean earth science society
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• v.21 no.2
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• pp.128-136
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• 2000

To understand the variation and transport pattern of suspended matters, salinity, tidal current and suspended matters in semiclosed Muan Bay have been monitored during winter and summer. The suspended matters show considerably seasonal variations with low concentration and homogeneity in the water column during winter season, but with high concentration and layering during summer season. Particularly, during summer season, the freshwater and the suspended matters influxed by the gate operation of the Youngsan River sea-dike are transported northward in accordance with the would flow into the inner-bay by relaxed flood currents after the construction of sea-dike and sea-walls in the Mokpo coastal zone. But, in the south bay-mouth, those matters outflow through the bay-mouth, resulting from tidal ebb dominance and asymmetry in the west bay-mouth. The residual suspended matter flux is much higher in the south bay-mouth(-0.0955kg/m ${\cdot}$ sec) than that of west bay-mouth(0.0078kg1m ${\cdot}$ sec). Accordingly, The Muan Bay is interpreted as erosion-dominated environments, and the erosion somewhat progresses in the intertidal flat of the bay.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.3
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• pp.23-31
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• 1987

In land treatment systems for organic waste removal, especially rapid intiltration method is well known as less climatic restrictions and less field area requirements as against the others. Therefore the present study on rapid infiltration is aimed to survey the waste removal rate, infiltration rate, variation of dissolved oxygen due to biological oxygen absorption and pH decrement using pilot infiltration column filled with permeable soil(sand) as media, also to find the waste load(COD) per unit area and nitrate conversion ratio from TKN. The results obtained here are as follows. 1) When the depth of sand layer is more than 1 meter, the COD removal would be reached steadly to 90% or more under the infiltration rate below 15~20cm/day, and would be no problem due to leached organic pollutants considering the depth of ground water table. 2) The COD removal per unit area($m^2$) can readily be expected to 10~14g/day with proper operation, and the decomposition of substrate would be attained mostly at the surface layer of the media. 3) Generally the conversion of TKN to the $NO_3{^-}$-N is seemed to be proportional to the COD removal rate if provided proper retention time.

• Korean Journal of Pharmacognosy
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• v.39 no.3
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• pp.199-202
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• 2008

A high performance liquid chromatographic (HPLC) method for the simultaneous determination of hesperidin and glycyrrhizin was established for the quality control of traditional herbal medicinal preparation, Pyungwi-san (PWS). Separation and quantification were successfully achieved with a Waters XTerra RP18 column ($5{\mu}m$, 4.6 mm I.D. ${\times}$ 150 mm) by gradient elution of a mixture of acetonitrile and water containing 0.03% phosphoric acid (pH 2.03) at a flow rate of 1.0 ml/min. The diode-array UV/vis detector (DAD) was used for the detection and the wavelength for quantification was set at 230 nm. The presence of hesperidin and glycyrrhizin in this extract was ascertained by retention time, spiking with each authentic standard and UV spectrum. All four compounds showed good linearity $(r^2>0.995)$ in a relatively wide concentration ranges. The R.S.D. for intra-day and inter-day precision was less than 7.0% and the limits of detection (LOD) were less than 60 ng. The mean recovery of each compound was 99.0-105.6% with R.S.D. values less than 4.0%. This method was successfully applied to the determination of contents of hesperidin and glycyrrhizin in three commercial products of PWS. These results suggest that the developed HPLC method is simple, effective and could be readily utilized as a quality control method for commercial PWS products.