• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.333-340
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• 1997

An analytical method was developed to determine residues of haloxyfop-R and its methyl ester in soils and soybeans using gas-liquid chromatography (GLC) with electron capture detector (ECD). Soil or soybean sample was acidified and extracted with acetone. The extract was then subjected to ion-associated partition to individually separate haloxyfop-R and the neutral methyl ester. One phase containing haloxyfop-R was methylated with $BF_3$/methanol, partitioned to n-hexane and analyzed by GLC/ECD. The other phase containing the methyl ester was further purified by Florisil column chromatography prior to GLC determination. No cross contamination was found between two phases containing each of the acid and methyl ester, thus two compounds can be separately determined as the identical haloxyfop-R-methyl. Overall recoveries of haloxyfop-R from fortified samples averaged 88.2${\pm}$3.9% (n=12) and 88.3${\pm}$4.0% (n=6) for soils and soybeans respectively, and those of haloxyfop-R-methyl showed mean values of 89.2${\pm}$4.0% (n=12) and 85.6${\pm}$5.6% (n=6). Detection limits of both haloxyfop-R and its methyl esterwere 0.005㎎/㎏ and 0.01㎎/㎏ for soil and soybean samples respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.5
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• pp.273-288
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• 1991

To elucidate the physiological and biochemical differences between chondrichthyes and osteichthyes, the properties of the specific digestive enzymes in cat-shark, Cephaloscyllium umbratile, and mackerel, Scomber japonicus, were studied. Homogenous trypsin proved through the disc-electrophoresis, SDS-PAG electrophoresis and gel filtration was obtained from the pancreas of cat-shark by $50-70\%$ saturated ammonium sulphate fractionation, DEAE-Sephadex A-50 column chromatography, benzamidine-Sepharose 6B affinity chromatography and Sephadex G-75-120 gel filtration. Two types of trypsins were also obtained from the pyloric caeca of mackerel by $30-70\%$ saturated ammonium sulphate fractionation and the slightly modified procedure from the method adopted in the purification of cat-shark trypsin. The two trypsins, designated trypsin A and B, were proved their homogeneity by disc- and SDS-PAG electrophoresis and gel filtration. The molecular weights of the trypsins were estimated to be 31,700 for cat-shark trypsin, 30,000 for mackerel trypsin A and 29,000 for mackerel trypsin B by SDS-PAG electrophoresis, but those were estimated to be 21,500 for cat-shark trypsin, 23,700 for mackerel trypsin A and 21,500 for mackerel trypsin B by gel filtration. The trypsins exhibited their optimum conditions at pH 9.0 and on temperature ranged from $45^{\circ}C\;to\;50^{\circ}C$ for cat-shark, and at pH 8.0 and a temperature of $50^{\circ}C$ for mackerel trypsin A and B, respectively. The cat-shark trypsin was stable at pH 10.0 and the temperature below $10^{\circ}C$, whereas the mackerel trypsin A and B, were stable in the range over pH 7.0 to pH 9.0 below $10^{\circ}C$ and at pH 8.0 below $35^{\circ}C$, respectively. The mackerel trypsins were severely inhibited by some heavy metal ions such as $Ag^{2+},\;Cu^{2+}\;and\;Hg^{2+}$ compared to cat-shark trypsin. All of the enzymes were also inhibited by antipain, leupeptin, TLCK(tosyllysine chloromethyl ketone) and SBTI(soybean trypsin inhibitor) remarkably. The inhibitory effects of PMSF(phenylmethane sulphonylfluoride), DFP(diisopropyl fluorophosphate) and benzamidine were indicated that these enzymes belong to serine-proteases.

• Analytical Science and Technology
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• v.14 no.4
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• pp.306-310
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• 2001

Ion chromatography was applied to determine iodide remained in sulfuric acid aqueous solution after adsorption procedure. Iodide was determined in 0.25 M, 0.5 M and 1 M sulfuric acid solution on time variation. Because sulfuric acid in solution plays as an oxidizer, the concentration of iodide decreased with increasing concentration or sulfuric acid. Thereafter, sulfuric acid was neutralized with sodium hydroxide. Good linearity(r=0.99999) was obtained at the range of 0-20 mg/L 1 in 0.5 M sodium sulfate matrix.

• KSBB Journal
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• v.15 no.4
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• pp.342-345
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• 2000

A novel pre-purification method was developed for producing peroxidase to guarantee high purity and yield from plant cell cultures in large-scale process. This method was a simple and efficient procedure for the isolation and pre-purification of peroxidase from the biomass consisting of active clay treatment followed by cationic exchange chromatography. The use of active clay in the pre-purification process allows for rapid and efficient separation of peroxidase from interfering compounds and dramatically increases yield and purity of crude peroxidase for purification steps compared to alternative processes. This pre-purification process serves to minimize the buffer usage size and complexity of the HPLC operations for peroxidase purification. This process is readily scalable to a pilot plant and eventually to a production environment where mass production of material are expected to be produced.

• Journal of Power System Engineering
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• v.4 no.3
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• pp.12-18
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• 2000

Recently, our world is faced with very serious and hard problems related to the air pollution due to the exhaust emissions of the diesel engine. So, lots of researchers have studied to reduce the exhaust emissions with various methods of diesel engine that influenced the environment strong. In this paper, the quantities of the low and high hydrocarbon among the exhaust emissions in diesel engine have been investigated by the quantitative analysis of the hydrocarbon $C_1{\sim}C_6$ using the gas chromatography. This study carried out by comparing the chromatogram with diesel fuel and three kinds of mixed fuels. One is the diesel fuel blended DGM(diethylene glycol dimethyl ether) 5%. Another is the diesel fuel blended DEE(diethyl ether) 25% and DMC(dimethyl carbonate) 10%. The results of this study show that the hydrocarbon $C_1{\sim}C_6$ among the exhaust emissions of the mixed fuels are exhausted lower than those of the diesel fuel at the all load and speed.

• Analytical Science and Technology
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• v.23 no.1
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• pp.97-101
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• 2010

(R)-N-3,5-dinitrobenzoyl (DNB) phenylglycinol derived chiral selector was used as a HPLC chiral stationary phase (CSP) for the resolution of racemic N-acylnaphthylalkylamines. In this study, determination of optical purity was performed by both chiral chromatography and NMR spectroscopy by using the (R)-phenylglycinol derived chiral selector. The data of accuracy and precision of each optical purity value are calculated from the results of NMR and HPLC experiments by comparing with true value. Average error of the NMR method was +2.2% with average RSD of 4.54%, while that of HPLC method was -3.5% with average RSD of 3.23%.

• Journal of the Korean Chemical Society
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• v.30 no.3
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• pp.312-319
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• 1986

Dodecyltrimethylammonium bromide (DTAB) was examined as a counter-ion in the investigation of capacity factor and separation of aromatic carboxylic acids on alkyl-modified silica (ODS) column as a stationary phase by ion-pair chromatography on reversed-phase system. The capacity factor of samples was influenced by the several factors such as a concentration of counter-ion as well as kinds and concentration of electrolyte, concentration of methanol in mobile phase and kinds and position of functional group in sample molecule. Some mixtures of samples were able to be separated under optimum condition.

• The Korean Journal of Food And Nutrition
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• v.10 no.3
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• pp.309-313
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• 1997

Bench scale Sikhyes were produced from rice and glutinous rice and limit dextrins in rice Sikhye and glutinous rice Sikhye were purified by ethanol precipitation and Biogel P-2 gel chromatography and FPLC on Superose 12 column and analyzed. The purified limit dextrin in rice Sikhye and glutinous rice Sikhye showed bot signal of $\alpha$-1,4- and $\alpha$-1,6-glucosidic linkage with its estimation ratio of 4.5:1 and 5.9:1, respectively, by 1H-NMR analysis. Limit dextrins were hydrolyzed by pullulanase. The enzyme hydrolysis products contained maltose, maltotriose, maltotetraose, maltopentaose and matohexaose. These results suggest that limit dextrins were composed of these maltoolgosaccharide series with $\alpha$-1,6-glucosidic bond.

• Journal of Plant Biology
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• v.35 no.2
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• pp.99-106
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• 1992

The endosperm protein, vicilin, of ginseng (Panax ginseng C.A. Meyer) was purified by ammonium sulfate precipitaion, gel permeation and ion exchange column chromatography. Vicilin is a glycoprotein composed of 2 subunits with molecular masses of 55,000 (large subunit) and 44,000 (small subunit). The anti-vicilin antibody was raised in rabbit, and purified by DEAE Affi-Gel Blue affinity chromatography. The endosperm cells of the seed were reacted with this anti-vicilin antibody and colloidal gold conjugated secondary antibody. Gold particles were labelled on the elaborating granules of Golgi complex, electron-dense granules and protein bodies in the endosperm cells. These results indicated that the vicilin, which was synthesized in rough endoplasmic reticulum and transported to Golgi, was elaborated in saccules of the Golgi and then transported into protein bodies by electron-dense granules.anules.

• Journal of the Korean Chemical Society
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• v.26 no.1
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• pp.49-57
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• 1982

Transesterification reactions were carried out with myo-inositol and five fatty acid methyl esters such as methyl laurate, methyl myristate, methyl palmitate, methyl stearate and methyl oleate in the dimethylsulfoxide solvent. Their products were separated by both thin layer chromatography and column chromatography, and myo-inositol monoesters were quantitatively separated by counter current distribution. We measured their surface tension, foaming power and emulsifying power, determined critical micelle concentrations by the color method, and evaluated their hydrophilic-lipophilic balance. The results show that myo-inositol monoesters exhibit surface activites.