• Korean Journal of Pharmacognosy
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• v.5 no.3
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• pp.173-177
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• 1974

Sterols were obtained from the non-saponifiable matters of ethereal and methanolic extracts of the root of Panax ginseng. The composition of sterols has been determined by gas chromatographic analysis. It was noted that campesterol, stigmastrol and ${\beta}-sitosterol$ were the major sterols in the ginseng. The results showed that contents of sterols were campesterol, $4.01{\sim}5.82%,\;stigmasterol,\;18.32{\sim}19.12%\;{\beta}-sitosterol,\;and\;75.11{\sim}77.74%$.

• Bulletin of the Korean Chemical Society
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• v.8 no.3
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• pp.133-137
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• 1987

Polysiloxane SE-54 liquid phase was immobilized on the support surface as coated in thin film via in-situ cross-linking. The cross-linking between liquid molecules was initiated by dicumylperoxide. Among the supports investigated, only Chromosorb W provided the cross-linkable surface. The optimal in-situ cross-linking was achieved when Chromosorb W was coated with 5% (w/w) SE-54 and cross-linked with 1% (w/w) dicumylperoxide. The cross-linked support was useful for the trace analysis as well as for the trace enrichment.

• Applied Biological Chemistry
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• v.12
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• pp.43-51
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• 1969

The purpose of this study was to determine protein amino acid contents of some Korean foods by gas-liquid chromatography, and to evaluate this technique as a procedure for the quantitative determination of amino acids in foods. The crude protein content of foods was also estimated from the nitrogen content. 1. Nitrogen content of each food sample was determined previously to adjust the amount of sample for GLC analysis 2. In the analysis of 17 known amino acids, a linear relationship was found between the weight of 13 amino acids of 17 amino acids, the internal standard as well as the injection volume of a mixture and the detector responses for the derivatives of the amino acids. No response for arginine, cystein, histidine, and tyrosine was observed. 3. The relative molar response (RMR) values for the 13 amino acids of standard solution relative to glutamic acid as '1.00' were obtained under normal operating conditions with a hydrogen flame ionization detector. 4. The recovery of amino acids from their mixtures with natural food materials was carried out. The recoveries were essentially quantitative except threonine and serine. An overall mean recovery of 11 amino acids was $101.4{\pm}8.4$ per cent before hydrolysis and $98.1{\pm}8.7$ per cent after hydrolysis of samples. 5. The comparative analysis of the acid hydrolysates of two food samples by gas-liquid and ion-exchange chromatographic analysis were carried out. In white-bait pemmican, only threonine and asparagine amounts by GLC analysis had similar values to those obtained by ion-exchange chromatography. The other seven amino acids gave higher values as measured by GLC than by ion-exchange. With the food sample, soybean, alanine, valine, asparagine, and glutamic acid were in good agreement in two analysis, while leucine, proline, threonine, phenylalanine, and lysine were found in slightly higher concentrations in the GLC analysis. 6. Grant variations of amino acid content were found among samples analyzed. The amino acid contents of each sample were compared with the values found in the literature.

• Mass Spectrometry Letters
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• v.14 no.4
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• pp.160-165
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• 2023

Citronella oil, an essential oil extracted through steam distillation from the leaves and stems of Cymbopogon, is a natural complex substance (NCS) regulated by the Korean government for its use in insect repellents. The component ratios of NCSs like citronella oil vary due to differences in manufacturing processes and origins, presenting a challenge in identifying and quantifying these substances in consumer chemical products. This study analysed ten commercially available products of the most commonly used types of citronella oil, specifically Java and Ceylon types, using gas chromatography (GC)-mass spectrometry (MS) and GC with flame ionization detection (FID). Through chromatographic data, we aimed to determine the components that can qualitatively identify citronella oil and the indicator ingredients that can be used for content analysis.

• The Korea Journal of Herbology
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• v.27 no.6
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• pp.43-48
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• 2012

Objectives : This study was investigated to determine the contents of pesticide residues and sulfur dioxide residues in commercial herbal medicines in Korea. Methods : Chromatographic test was performed on 100 samples consisted with 10 kinds of medicinal plants including improted and domestic products. To establish 19 pesticide residues (DDE, DDD, DDT, Dieldrin, Methoxychlor, BHC isomers, Aldrin, Endosulfan isomers, Endrin, Captan, Procymidone, Chlorpyrifos and Imidacloprid) in commercial herbal medicines, chromatographic equipments were used with the gas chromatography-mass detector and gas chromatography-electron capture detector for qualitative analysis. The imidacloprid analysis was performed by high performance liquid chromatograpgy-ultraviolet detector at 270 nm UV wavelength. The contents of sulfur dioxides were analyzed by modified Monnier-Williams method. All methods were based on notification procedure of Korea Food & Drug Administration (KFDA). Results : The residual pesticides were not founded in improted and domestic samples. Among 100 samples, the residues of sulfur dioxide in 73 samples were not detected and 25 samples showed contents in the range of 0~21.90 mg/kg. The excess samples of MRLs were 2 samples (30 mg/kg to medicinal herbs), Asiasari Radix et Rhizoma (Imported product) and the average amount of sulfur dioxide in 2 unsuitable samples were 14.83 mg/kg. These samples were found to transgress KFDA regulatory guidance of residual sulfur dioxide. Conclusion : These results are able to use as basic data to improve the reliability and value of commercial medicinal herbs.

• Journal of Environmental Science International
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• v.18 no.12
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• pp.1369-1381
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• 2009

The simultaneous determination of residual pesticides was developed using a gas chromatography. In this study, a simple and reliable methodology was improved to detect 175 kinds of residual pesticides by a liquid-liquid extraction procedure, followed by chromatographic analysis by gas chromatography. The 175 kinds of residual pesticides was classified into 4 groups according to the chemical structure, column type, resolution and sensitivity. The soybean sample selected for recovery experiment was not detected any pesticides. The recovery rates were ranged from 70.6% to 119.7% in most pesticides. The relative standard deviation (RSD 0.3~5.6%) was lower than 5.6% in all cases. The limits of detection (LOD) was lower than the maximum residue levels established by Korean legislations. The method has been successfully applied to the analysis of approximately 130 real samples.

• Korean Journal of Food Science and Technology
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• v.26 no.2
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• pp.162-166
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• 1994

A rapid gas chromatographic (GC) profiling method for the simultaneous analysis of volatile and nonvolatile organic acids was applied to alcoholic beverages (white wine, red wine, brandy, and beer). It involves the solid-phase extraction of organic acids using Chromosorb P as the sorbent and diethyl ether as the eluent with subsequent triethylamine treatment. The resulting triethylammonium salts of acids were directly converted to volatile tert.-butyldimethylsilyl derivatives, which were analyzed by dual-capillary column GC and GC-mass spectrometry. From the alcoholic beverages studied, more than 29 organic acids were detected. When the simplified retention infer (RI) spectra of organic acids, and the direct comparisor method between alcoholic beverages and a test sample were attempted to identify a test sample, it was quickly recognized to be a red wine with the 998 ppt match quality value.

• Journal of Nutrition and Health
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• v.12 no.2
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• pp.75-85
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• 1979

The Korean origin sunflower (Helianthus Annus Linn.) seed of netural lipid were analysed by thinchrography, High performance liquid chromatography, preparative Thinlayer and Gas liquid chromatography. 1) The seed oil triglyceride components were conveniently separated based on their degree of unsaturation by employing the chromatography on silica gel sintered rod impregnated with 12.5% silver nitrate. Sunflower seed oil was composed of triglyceride, especially trilinolein 57. 74% triolein 25.28%, tripalmitin 7 55% ana tristearin 9.43% by a thinctrography. 2) The fatty acid compositions of seed oil have been determined by a high performance liquid chromatographic analysis using a ALC/GPC 244 type from Waters Association (Japan) with ${\mu}$ Bondapak FFAA column. It contained stearic acid 8.59%, oleic acid 27. 19%, palmitic acid 7.50% and linoleic acid 56.72% respectively. 3) The composition of sterols were determined by a preparative Thinlayer and Gas liquid chromatographic analysis. It was noted that sitosterol was the major sterol in the Korean sunflower seed. The results showed that contents of sterols were cholesterol trace, campesterol $13_.^{22\sim}13.9%$, stigmasterol $13.8{\sim}14.1%$, If, sitosterol $58.4{\sim}60.7%$, ${\vartriangle}^7$-stigmastenol $10.2{\sim}10.5%$ and ${\vartriangle}^{7,24(25)}$-stigmastenol $3.6{\sim}3.8%$ by method of planimetry and triangulation.

• Journal of Life Science
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• v.13 no.2
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• pp.214-222
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• 2003

The microorganism isolated from soil was identified as Bacillus coagulans by morphological and biochemical analyses and API-50CH/B kit, which was an identification kit for Bacillus species, and named as B. coagulans DL-1. It produced an extracellular biopolymer. Maximum production of biopolymer was 5.00 $\pm$0.15 g/$\ell$ in a $7\ell$bioreactor with an aeration rate of 1.0 vvm and an agitation speed of 500 rpm when concentrations of glucose and yeast as the optimal carbon and nitrogen sources were 2.0% (w/v) and 0.25% (w/v), which were optimized with a flask scale. Gas chromatographic analysis showed that the biopolymer producded by B. coagulans DL-1 consisted of glucose and rhanmose and their molar ratios was about 9 : 1. Its average molecular weight was 2.80$\times$$10^5$ with gel permeation chromatographic (GPC) analysis.

• Analytical Science and Technology
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• v.15 no.5
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• pp.445-450
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• 2002

A sensitive gas chromatographic method has been established for the determination of total iodide in seawater as their volatile organic derivative. The method is based on the formation of 4-iodo-2,6-dimethylphenol with 2,6-dimethylphenol in matrix and a single-step extraction of the derivative with ethyl ether, which are then measured by gas chromatography-mass spectrometry (selected ion monitoring). Iodate in sea water was completely reduced to iodide with ascorbic acid and acetic acid. The detection limit was 0.1 ng/mL in seawater and the calibration curve showed good linearity with r=0.9997. The method was sensitive, reproducible and simple enough to permit the reliable routine analysis of total iodide in seawater. Total iodide in sea water was found about 30 ng/ml.