• Archives of Pharmacal Research
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• v.17 no.5
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• pp.360-363
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• 1994

Column--swtiching technique with a reversed-phase high performance liquid chromatographic method has been developed for the routine analysis of radioiodinated insulin and its degadation products in biological fluids. The diluted biological samples were loaded onto a precolumn packed with LiChrosorb RP-8 $(25-40{\;}{\mu}m)$ using 0.1% trifuoroacetic acid (TFA) in water as a washing solvent. After valve switching, the concentrated insulins were eluted in the back-flush mode and separated by a W-Porex $C_{18}$ column with a gradient of 0.1% TFA in water and 0.1% TFA in acetonitrile as the mobile phase. The method showed good precision, accuracy and speed with the detection limit of 20 pg/ml. Total analysis time per sample was about 40 min and the coefficients of variation were less than 8, 2%.

• Archives of Pharmacal Research
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• v.17 no.6
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• pp.424-427
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• 1994

An acinomycin complex isolated from culture broth of a soil microorganism, SNUS 9305-011 has been examined by High performance liquid chromatography (HPLC). From the analysis of the fractions obtained by column chromatography of the ethyl acetate extract, three actinomycin components are confimed . The HPLC analysis is carried out with a CN-bonded nucleosil column. Comparison of the retention times of the components with those of actinomycin D, C complex, $X_{o{\beta}$, and V and suggests that they are different actinomycins. FBA mass spectra fo the coponents also shows different molecular ions from those of standards and other reported actionbmycins. The present work has demonstrated that actinomycin components can be separated by a CN-bonded HPLC column, and that ocmparison of their HPLC chormatograms with authentic smaples and information on their molecular ions can be successfully employed for indentification of actionmycins.

• Archives of Pharmacal Research
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• v.17 no.6
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• pp.458-461
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• 1994

A new high-performance liquid chromatographic method with column switching has been onto a Bondapak phenyl/corsil $(37-50{\;}{\mu}m)$ precolumn and polar plasma components were washed with 0.06 M borate burffer. After valve switching, the concentrated drug were eluted in the back-flush mode and separated on a ${\mu}-Bondapak$ C18 column with acetonitrilke-phosphate buffer as the mobile phae. The method showed excellent precision, accuracy and speed with detection limit of $0.01{\;}{\mug}/ml^{-1}$. Total analysis time per smaple was less than 20 min and the coefficients of variation for intra and inter-assay were less than 5.635. This method has been successfully applied to plasma smaples from eats after oral administration of omeprazole.

• Analytical Science and Technology
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• v.25 no.4
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• pp.207-213
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• 2012

Analysis of the aroma constituents present in the rose essential oil of Chinese Kushui type (Rosa sertata ${\times}$ Rosa rugosa) by GC-FID and GC-MS was performed independently as an expert for the inter-laboratory round-robin test to verify reproducibility according to the decision of the preliminary meeting of ISO/TC-54 (Shanghai, Sep. 14-15, 2010). Total 179 peaks (using SPB-1 apolar column), 165 peaks (using DB-624 intermediate polar column), and 162 peaks (using Supelcowax-10 polar column) were separated by GC-FID, respectively. Major constituents (over 5%) by GC-FID were ${\beta}$-citronellol (41.6~46.7%), geraniol (9.7~11.0%), and nerol (3.4~4.5%). ${\beta}$-Citronellol peak was overlapped with nerol peak on SPB-1 and DB-624 columns, whereas the two peaks were separated each other on Supelcowax-10 column. Our results were generally consistent with Chinese data (ISO/DIS 25175); however, a peak of phenethyl alcohol separated by using PEG (Supelco wax) column was found at the quite different retention time. Comparative analysis was conducted using Bulgarian rose (Rosa damascena Miller) oil and perfume. Bulgarian rose oil showed rich amounts of characteristic aroma constituents than the essential oil of Chinese Kushui type.

• Mass Spectrometry Letters
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• v.2 no.4
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• pp.92-95
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• 2011

Pyrophosphates are the key intermediates in the biosynthesis of isoprenoids, and their concentrations could reveal the benefits of statins in cardiovascular diseases. Quantitative analysis of five pyrophosphates, including isopentenyl pyrophosphate (IPP), dimethylallyl pyrophosphate (DMAPP), geranyl pyrophosphate (GPP), farnesyl pyrophosphate (FPP), and geranylgeranyl pyrophosphate (GGPP), was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in negative ionization mode. After dilution with methanol, samples were separated on a 3 ${\mu}m$ particle multi-modal $C_{18}$ column ($50{\times}2$ mm) and quantified within 10 min. The gradient elution consists of 10 mM ammonium bicarbonate and 0.5% triethylamine (TEA) in water and 0.1% TEA in 80% acetonitrile was used at the flow rate of 0.4 mL/min. Overall recoveries were 51.4-106.6%, while the limit of quantification was 0.05 ${\mu}g$/mL for GPP and FPP and 0.1 ${\mu}g$/mL for IPP, DMAPP, and GGPP. The precision (% CV) and accuracy (% bias) of the assay were 1.9-12.3% and 89.6-111.8%, respectively, in 0.05-10 ${\mu}g$/mL calibration ranges ($R^2$ > 0.993). The devised LC-MS/MS technique with the multi-modal $C_{18}$ column can be used to estimate the biological activity of pyrophosphates in plasma and may be applicable to cardiovascular events with cholesterol metabolism as well as the drug efficacy of statins.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.732-738
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• 2001

This study was attempted to isolate and identify the anticancer compounds from Eucommia ulmoides leaves using a human colon cancer cell line HCT-116. The petroleum ether extracts with anticancer activity was chromatographed on silica gel TLC and finally anticancer compounds was purified by HPLC. Their chemical structures were roughly elucidate by UV-VIS absorption spectral data HPLC elution pattern and FAM/MS spectroscopy. From this study these compounds were suspected to be pheophytin a formed by the removal of $Mg^{2+}$ from chlorophyll a and pyropheophytina formed by the removal of acetate group from pheophytin a respectively. To confirm the anticancer effects against HCT-116 cancer cell petroleum ether extract fractions of column chromatography and fractions separated on TLC were tested. All samples tested including the extract of petroleum ether fractions of column chromatograph and three bands (0.13,0.19,0.25) of TLC appeared to inhibit the growth of HCT-116 cancer cell however especially 0.19 and 0.25 fractions separated on TLC plate revealed the strongest effect. These results suggest that chlorophyll derivatives in Eucommia ulmoides may be potential anticancer agents against a human colon cancer cell HCT-116.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.21-27
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• 2018

FRN (Full range Naphtha) is distilled from crude oil in a Naphtha Splitter Unit and is separated into the Light Straight Naphtha, Heavy Naphtha, and kerosene according to the boiling point in sequence. This separation is conducted using a series of binary-like columns. In this separation method, the energy consumed in the reboiler is used to separate the heaviest components and most of this energy is discarded as vapor condensation in the overhead cooler. In this study, the first two columns of the separation process are replaced with the Petlyuk column. A structural design was exercised by a stage to stage computation with an ideal tray efficiency in the equilibrium condition. Compared to the performance of a conventional system of 3-column model, the design outcome indicates that the procedure is simple and efficient because the composition of the liquid component in the column tray was designed to be similar to the equilibrium distillation curve. An analysis of the performance of the new process indicated an energy saving of 12.3% under same total number of trays and with a saving of the initial investment cost.

• Resources Recycling
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• v.22 no.3
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• pp.65-72
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• 2013

A vertical column pneumatic separator was modified to improve its separation performance. A branch column was installed at the center of the main column, which created a bypass flow and changed the flow rate of the main column before and after the branch column. To separate a mixture comprising light and heavy materials, the airflow in main column after the branch column was set to lift the only light materials and the airflow in main column before the branch column was set to prevent the flow of the light materials from flowing downwards. Materials directed into the branch column were separated from the flow and returned to the feeder through the cyclone linked to the branch column. The performances of the straight-type separator and the modified separator were compared using glass and zirconia beads with a narrow size distribution.

• Journal of the Korean Society of Tobacco Science
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• v.2 no.1
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• pp.1-7
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• 1980

Gel filtration column chromatography (Sephadex G-75), dialysis an d Brushite column chromatography were carried out to separate the brown pigmented macromolecule from water extracts of the cured leaf tobaccos. The two distinct macromolecules having different molecular weight were separated by the Sephadex column chromatography. Brushite also separated two different species of macromolecules which might have different electronic structures. According to the enzymatic degradation of protein in Burley and Hicks, chymotrypsin showed the best degradation ratio, ie., 16-30% in Burley and 38-57% in Hicks. Similar effect was observed with pepsin. However, very low effect of degradation was revealed with trypsin. The sample treated with the proteolytic enzymes revealed the disappearance of the first peak and the slight decrease of the 2nd peak height in the separation profile of Sephadex. After dialysis, the brown pigmented macromolecule was pyrolyzed at $300^{\circ}C$ and the strongly fluorescent components not identified before pyrolysis were detected with TLC separation. Absorption spectrum of these fluorescent compounds was monitored in benzene and the absorption maxima at 265nm and 275 nm were obtained. Considering absorption maxima and shape of the spectrum, those fluorescent compounds seem to be PAH derivatives.

• YAKHAK HOEJI
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• v.17 no.1
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• pp.41-43
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• 1973

Trace-amounts of Diptered and DDVP in fishes could be separated and identified by thin layer chromatography and gas chromatography with DEGS-H$_{3}$PO$_{4}$ column.