• Applied Biological Chemistry
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• v.35 no.2
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• pp.132-138
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• 1992

For effective determination of methylthiohydantoin amino acids(MTHs) by gas liquid chromatography in the protein sequencing, derivatization with N-methyl-N-(tert.-butyl-dimethylsilyl)trifluoroacetamide(MTBSTFA), a new silylating reagents, was attempted instead of trimethylsilyl(TMSi) derivatives by N,O-bis(trimethylsilyl)trifluoroacetamide(BSTFA) used up to the present and N(O)-butyldimethylsilyl MTHs derivatized by MTBSTFA were analysed on HP-1 capillary column. Twenty one protein amino acids except cystine were indentified. Especially arginine that did not detected with TMSi derivative on packed column until now was resolved by derivatization with MTBSTFA. N(O)-butyldimethylsilyl MTHs showed multiple peaks by MTBSTFA were proline, isoleucine, glycine and tyrosine and hydroxyproline especially showed several extraneous peaks more than two. Calibration curves of N(O)-butyldimethysilyl MTHs of amino acids in the range of $2.5\;nmol{\sim}7.5\;nmole$ showed good linearity. however, those of lysine, histidine and arginine showed linearity in the range of $5.0\;nmole{\sim}15.0\;nmole$. Correlation coefficients and regression coefficients of all calibration curves were highly significant(p<0.001).

• Korean journal of food and cookery science
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• v.6 no.4 s.13
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• pp.27-32
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• 1990

Lipids of Job's tears (Yullmoo) were extracted by the mixture of chloroform: methanol (2:1, v/v) and from these lipids, triglycerides were separated by column chromatography (Sephadex G-25 column) and then confirmed by thin layer chromatography (TLC) and reconfirmed by gas chromatography (GC). The triglycerides were fractionated into 6 groups on the basis of their partition numbers (PN) by reverse phase high performance liquid chromatography (HPLC) on a column Shimpack CLC-ODS using tetrahydrofuran-acetonitril (25:75) mixture as a solvent. Each of these collected fractions gave one to two peaks in the GC chromatograms according to the acyl carbon number (CN) of the triglyceride and fatty acid composition of the triglycerides were also analyzed by GC. From the results, the major triglycerides of Job's tears lipids were estimated to be C18:1 C18:2 C18:2 (OLL, 38.2%), C16:0 C18:2 C18:3 (PLLn, 15.7%), C18:1 C18:1 C18:2 (OOL, 12.6%).

• Applied Biological Chemistry
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• v.27 no.4
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• pp.259-263
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• 1984

Volatile flavor components of raw ginseng were collected from the manufacturing process of ginseng extract. Flavor components were separated by capillary column chromatography using SE-54 stationary phase and individual components were identified by means of GC/MS. Twenty six compounds including monoterpenes, esters, ethers, and sesquiterpenoids were tentatively identified. Major flavor components characteristic to ginseng appeared to he sesqiterpenoids such as ${\alpha}-gurjunene,\;{\beta}-maaliene,\;{\alpha}-guaiene,\;{\beta}-patchoulene$, (-)aromadendrene, and ${\beta}-elemene$.

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.165-175
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• 2010

A gas chromatographic (GC) method was developed to determine residues of captan, folpet, captafol, and chlorothalonil, known as broad-spectrum protective fungicides for the official purpose. All the fungicide residues were extracted with acetone containing 3% phosphoric acid from representative samples of five agricultural products which comprised rice, soybean, apple, pepper, and cabbage. The extract was diluted with saline, and dichloromethane partition was followed to recover the fungicides from the aqueous phase. Florisil column chromatography was additionally employed for final cleanup of the extracts. The analytes were then determined by gas chromatography using a DB-1 capillary column with electron capture detection. Reproducibility in quantitation was largely enhanced by minimization of adsorption or thermal degradation of analytes during GLC analysis. Mean recoveries generated from each crop sample fortified at two levels in triplicate ranged from 89.0~113.7%. Relative standard deviations (RSD) were all less than 10%, irrespective sample types and fortification levels. As no interference was found in any samples, limit of quantitation (LOQ) was estimated to be 0.008 mg/kg for the analytes except showing higher sensitivity of 0.002 mg/kg for chlorothalonil. GC/Mass spectrometric method using selected-ion monitoring technique was also provided to confirm the suspected residues. The proposed method was reproducible and sensitive enough to determine the residues of captan, folpet, captafol, and chlorothalonil in agricultural commodities for routine analysis.

• The Korean Journal of Pesticide Science
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• v.4 no.2
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• pp.11-17
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• 2000

Optimum parameters were investigated for the simultanious analysis of 24 pesticide residuces using gas-liquid chromatography with electron capture detection. Electronic pressure control(EPC) on column enhanced resolution of 24 analyzes. Using DB-17, SPB-608, and Ultra-2 capillary column without EPC incomplete separation was observed in some pairs of pesticides. When EPC function was adopted, no severe overlapping was observed on SPB-608 column in every pesticides except vinclozolin/acetochlor pair. Total running time was 45 min, much shorter than $69{\sim}81$ min when used without EPC. Limit of determination of each analyze ranged $0.1{\sim}12.9$ ng/mL.

• Journal of Environmental Health Sciences
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• v.27 no.1
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• pp.88-92
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• 2001

The simultaneous analytical method for 37 residual pesticides was developed by a gas chromatography with $^{63}$ Ni electron capture detector. Pesticides added in soybean sample were extracted with 70% acetone in water and methylene chloride in oder, and then cleaned up via open-column apparatus packed with florisil and alumina N. The Ultra-2 fused capillary column was used to separate the products. The resolution between the last isomeric peak of cypermethrin (56.398 min) and the first isomeric peak of flucythrinate (56.421 min) was not satisfactory and the last isomeric peak of fenvalerate(58.783 min) and the first isomeric peak of fluvalinate(58.835 min) was overlapped. Except for $\alpha$-BHC, dichlofluanid, captan, and captafol, most recoveries were showed over 70%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1033-1037
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• 2001

Garlic oleoresins were made by extracting with four solvents of methanol, methyl acetate hexane and acetone from chopped garlic, respectively, and the volatile compounds of each extract were separated by gas chromatography installed with polar (supelcowax-10$^{TM}$) and nonpolar (HP-5) capillary columns, respectively, and identified by matching mass data of mass selective detector and Kovat\`s retention index with references. The numbers of the volatile compounds identified the garlic oleoresin by polar and nonpolar columns from in garlic oleoresins were 41 and 32, respectively. In polar column, 13 pyrans, 11 sulfur-containing compounds 6 furans 2 alcohols and 2 heterocyclic compounds were identified. In nonpolar column, 11 sulfur-containing compounds 5 acids 3 furans and eugenol were identified. The major sulfur-containing compounds identified from the oleoresins were 3, 3'-thiobis-1-propene, methyl 2-propenyl disulfide, dimethyl trisulfide, di-2-prnpenyl-trisulfide, 2-thiophenecarboxylic acid. The amount of these sulfur-containing compounds isolated from the oleresins were more abundant in polar column than in nonpolar column. The most efficient solvent for extracting volatile compounds of garlic was methanol but the most useful solvent for extracting sulfur-containing compounds was methyl acetate of less polarity.y.

• YAKHAK HOEJI
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• v.32 no.1
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• pp.6-13
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• 1988

A gas chromatographic method is described for the determination of volatile free acids(VFAs) in body fluids. VFAs were trace enriched from body fluids by liquid-solid extraction using Chromosorb P as the solid sorbent and ether as the eluant. The enriched VFAs were injected in splitless injection mode onto a HP-20M fused silica capillary column. The flame ionization detector was used as the detector. The present method was applied to the profiling of VFAs in body fluids from patients suffering from the infectious disease, hepatitis. The VFAs concentrations were high in saliva of hepatitis patients and isobutyric acid detected in sera of hepatitis patients compared to healthy subjects.

• Analytical Science and Technology
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• v.5 no.2
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• pp.159-167
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• 1992

An improved and accurate method for the determination of linear alkybenzene sulfonate(LAS) in river water is described by using gas chromatography and GC/MS. The gas chromatograph equipped with BP-5 capillary column was satisfactory for isolation of the homologues and isomers of LAS in river water. Four LAS homologues, $C_{10}$, $C_{11}$, $C_{12}$, $C_{13}$ alkyl chains were determined in Jungrang stream, Jinwi stream and down stream of Han river tributary. Especially $5-C_{11}$, $6-C_{11}$, $2-C_{12}$ and $6-C_{13}$, $7-C_{13}$ of LAS were identified by mass chromatogram. Different composition of LAS in standard and river water expressed the distribution and fate of LAS in river water. The remarkable reduced content of $C_{12}$ and $C_{13}$ in river water implied that the biodegradation of LAS more easily occured in longer alkylchain one. This method would be applicable for determination of LAS in water with high resolution and sensitivity.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2418-2422
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• 2011

The enantiomeric separation of lactic acid for its absolute configuration has become important task for understanding its biological origin and metabolic process involved in the formation of lactic acid. It involves the conversion of enantiomers as diastereomeric O-pentafluoropropionylated (S)-(+)-3-methyl-2-butyl ester and the direct separation by gas chromatography-mass spectrometry on a achiral capillary column. The (R)- and (S)-lactic acids were completely separated with a high resolution of 1.9. The newly developed method showed good linearity (r ${\geq}$ 0.999), precision (% relative standard deviation = 3.4-6.2), and accuracy (% relative error = -7.7-1.4) with the detection limit of 0.011 ${\mu}g/mL$. When the method was applied to determine the absolute configuration of lactic acid in Lactobacillus delbrueckii subsp. lactis 304 (LAB 304), the composition (%) of (R)-lactic acid in the cell pellet and in the culture medium were $89.0{\pm}0.1$ and $78.2{\pm}0.4$, respectively. Thus, it was verified that the present method is useful for the identification and composition test of lactic enantiomers in microorganisms.