• YAKHAK HOEJI
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• v.19 no.4
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• pp.240-245
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• 1975

The quantitative analysis of ethambutol.2HCl as well as commercial ehambutol preparations was undertaken by gas-liquid chromatography by finding optimum conditions, such as the use of internal standard, stability of an ethambutol-2HCl-caffeine standard solution, and the effect of column temperature, N, O-bis-(trimethylsily) acetamide [B.S.A.] concentrations and other substances present in the preparations. Under the chromatiographic conditions, an ethambutol-2HCl. caffeine standard, 9 min, 30sec. The relative molar response of ethambutol.2HCl and caffeine studied was 2.08. Ethambutol.2HCl could be quantitated up to 1$\times$10$^{-8}$ moles. the possible decomposition of B.S.A. due to the moisture when tested and the incoplete reaction for silylation could be minimized.

• YAKHAK HOEJI
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• v.47 no.6
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• pp.352-355
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• 2003

Voglibose is a new antidiabetic agent currently being devoloped by the research and development division of Takeda chemical industries Ltd. in japan. Basic research for the determination of voglibose in pharmaceutical preparation by gas chromatography. This method utilizes voglibose to give its acyl compound with acetyl anhydride in pyridine solution. The calibration curve for voglibose was linear over the concentration range of 0.08∼0.32 $\mu\textrm{g}$/${mu}ell$ with correlation coefficient of 0.996. The detection limit for voglibose was 0.016 $\mu\textrm{g}$/${mu}ell$ and the result of recovery test was 101.6% with relative standard deviation of 2.0% by standard addition method.

• Nuclear Engineering and Technology
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• v.7 no.1
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• pp.3-8
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• 1975

The quantitative analysis of various kinds of free amino acids contained in blood serum of patients with chronic mandible ostities, epidermic hemorrhagic fever, chronic renal failure and liver cirrhosis were measured with the gas-liquid chromatography (G. L. C.). The results compared with the quantity of free amino acids of healthy persons. It was found that the quantity of free amino acids were differently contained in blood serum in accordance with kinds of patients.

• Journal of Environmental Science International
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• v.6 no.2
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• pp.183-187
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• 1997

Organophosphate pesticides were extracted with 70% acetone and then transferred to dichloromethane. Extracts were applied to open-column chromatography with florisil. The florial extract was analyzed by gas chromatography with nitrogen-phosphorus detector(GC/NPD). Recoveries of the 18 organophosphate pesticides were ranged from 88.7% to 100. 0% for the narrow-bore capillary GC(Ultra-21. The minimum detectable level of this analytical method was 0.019 - 0.035 mg/kg. Sample throughput(extraction, open-column chro- matography, and GC analysts) was decreased considerably (8h per sample).

• Journal of Environmental Science International
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• v.6 no.4
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• pp.385-389
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• 1997

Pesticide residues were extracted with 70% acetone and transferred to dichloromethane. Extracts were applied to open-column chromatography with florisil and alumina-N. The final extract was analyzed by gas chromatography with electron-capture detector(GC /ECD) and nitrogen-phosphorus detector(GC/NPD). Recoveries of the 17 organochlorine pegticides were ranged from 60.8 to 84.9% and those of 15 organophosphate pesticides, from 70.5% to 100.0%(except phosmet and azlnphos-methyls. The minimum detectable levels of this analytical method were low(0.021-0.058mg/kg).

• Journal of the Korean Home Economics Association
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• v.7 no.1
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• pp.74-77
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• 1969

• KSBB Journal
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• v.30 no.4
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• pp.141-147
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• 2015

The convenient determination of methylsulfonylmethane (MSM) for a commercially available dietary supplement was developed using gas chromatography (GC)-flame ionization detector (FID). Chromatography was performed on a capillary column ($0.32mm\;I.D{\times}30m$, $0.25{\mu}m$) coated with dimethylpolysiloxane using diethylene glycol methyl ether as an internal standard. The performance characteristics of GC were evaluated in terms of selectivity, linearity, precision, accuracy, recovery, limit of detection (LOD) and limit of quantification (LOQ). The calibration curve was highly linear (the coefficient of determination: 0.9979) within the concentration range of $10.0{\sim}800.0{\mu}g/mL$ for MSM. The recoveries for three fortified concentrations were 96.7~97.1%, 96.6~97.3% and 96.8~97.2%, respectively. The LOD and LOQ of the method were $0.29{\mu}g/mL$ and $0.97{\mu}g/mL$, respectively. All obtained results were acceptable according to the guidelines of the Association of Official Analytical Chemists for dietary supplements. Thus, the validated analytical method using the GC-FID system is suitable for the determination of MSM in dietary supplement formulations for quality control.

• 유체기계공업학회:학술대회논문집
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• 1999.12a
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• pp.90-96
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• 1999

In contracts for sales of natural gas between sellers and buyers, it is not suncient to only measure a volumetric quantity of gas in flowing conditions in metering station. Therefore the measured volumetric quantity must be converted to that of reference conditions. The density of the natural gas required in such a calculation can be measured directly or estimated from the equation of sate or any other experimental methods. The specific gravity meter is the apparatus used to measure the density of fluids under the reference conditions and it can be widely used in industrial areas, especially in massive flow rate natural gas industry. This study has been carried out in an attempt to improve measurement accuracy of natural gas flow rate calculation, providing the adequate installation and proper operation conditions of specific gravity meter. The test results are 1) the density measurement errors in case of using methane and standard gas as calibration gases are smaller than using methane and nitrogen gas, 2) the periodical calibration to maintain accurate density measurements is essential, and 3) the specific gravity meter is sensitive to changes of environmental conditions, especially environmental temperature surrounding the specific gravity meter.

• Korean Journal of Food Science and Technology
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• v.8 no.2
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• pp.85-89
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• 1976

The separation and determination of dicarbonyls such as diacetyl, methylglyoxal and triose reductone in their mixed aqueous solution were carried out by means of gas chromatography with transformation of these compounds into quinoxaline derivatives with o-phenylenediamine. A column used for this experiment was consisted of Celite 545 (80-100 mesh) coated with 5% Silicon Gum SE-30. The column temperature was $180^{\circ}C$. It is desirable that this approach will be applicable to dicabonyl study in gas chromatographic determination.

• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.997-1001
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• 2000

The organic acids in 3 kinds of medicinal herbal extracts were screened and compared each other according to their organic acid contents by an efficient gas chromatographic method. It involves solid-phase extraction of organic acids using Chromosorb P with subsequent conversion to stable tert-butyldimethysilyl derivatives for the direct analysis by capillary column gas chromatography and gas chromatography-mass spectrometry. Total of 24 organic acids were reproducibly identified from 3 kinds of herbal extracts. When the GC profiles were simplified to their retention index spectra, characteristic patterns were obtained for each herb sample. As expected, three kinds of herbal extracts showed three distinct patterns.