• Natural Product Sciences
• /
• v.22 no.4
• /
• pp.259-262
• /
• 2016

The content analysis of fatty acids in Perilla cultivars and commercial oils is conducted through gas chromatography with a flame ionization detector. Results show that Perilla cultivars, such as Deulsaem and Daesil, contain high amounts of ${\alpha}-linolenic$ acid (262.22 and 261.97 mg/g, respectively). Among commercial oils, Perilla oil contains a higher amount of ${\alpha}-linolenic$ acid (515.20 mg/g). Accordingly, ${\alpha}-linolenic$ acid is a major fatty acid of Perilla cultivars and oil. Therefore, Perilla cultivars could be used as a food supplement for nutritional and pharmaceutical purposes.

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

• Journal of Nutrition and Health
• /
• v.16 no.2
• /
• pp.107-114
• /
• 1983

There has been no specific test available for identifying the sesame oil among common edible oils. As the contents of sesamin and the ratio of sterols allowed the estimation for the genuine sesame oil, the author investigated to establish some instrumental methods for verification of genuine sesame oil and its distribution in the market. The sesame oil was saponified and the sesamin and sterols were isolated from the unsaponiable fraction by Florisil column chromatography. The individual components were determined by gas- chromatography and sesamin standard (purified sesamin) was obtained by silicagel column chromatography. The gas- chromatographic condition using Flame Ionization Detector supported on 10% OV-101 with di-(2-ethylhexyl) sebacate as an internal standard was suitable, and quantitation of sesamin and sterols, including campesterol, stigmasterol and ${\beta}-sitosterol$ was carried out. The results of this study showed that contents of sesamin in genuine sesame oil were 0.3-0.5% and the ratio of stigmasterol to compesterol was 0.3-0.6 and ${\beta}-sitosterol$ to campesterol 3.0-3.8. The 50 samples from the markets in Seoul were composed of 70% genuine sesame oil, and others were mixed with palm oil, rape seed oil and soybean oil.

• Journal of Ginseng Research
• /
• v.14 no.3
• /
• pp.353-356
• /
• 1990

The isolation of volatile compounds by vacuum-distillation with freeze-drying was tested 1 with fresh ginseng roots. The roots were frozen at-8$0^{\circ}C$; they were dried at-4$0^{\circ}C$ tinder vacuum(40 tory), for 24 hours; and the ice condensed at the silrface of condenser in the freeze-dryer was thauved at room temperature. The ether extract of the resulting aqueous solution was analyzed by gas chromatography (GC) equipped with a flame ionization detector (FID) or a nitrogen-phosphorils detecto(NPD) and by gas : chromatography/mass spectrometry(GC/MS). More than forty peaks were observed in the CG(FID) profile. and more than ten peaks were observed in the GC(NPD) profile. Among them, thirteen components 1including one aldehyde, four hydrocarbons, two esters, folly alcohols, and two vyrazines were identified: six components the molesuiar ions of which were m/z, 204 were estimated to be a series of azulene compounds; and the other components unidentified were estimated to have molecular weights of lower than 254. Therefore, the freeze-drying technicue is thought to be usefu1 for the isolation of volatile compounds of such low molecufilar weights from vegetables, fruits and biological fluids as well as fresh ginseng roots under the tested conditions.

• Analytical Science and Technology
• /
• v.34 no.5
• /
• pp.202-211
• /
• 2021

Volatile organic compounds (VOCs) in hazardous air pollutants (HAPs) have been regulated by the Air Pollution Control Act (1978) and their atmospheric concentrations have been monitored in 39 monitor sites in Korea. However, measurement standards of volatile organic compounds (VOCs) in HAPs at ambient levels have not been established in Korea. Primary reference gas mixtures (measurement standards) at ambient levels are required for accurately monitoring atmospheric VOCs in HAPs and managing their emissions. In this study, primary reference gas mixtures (PRMs) at 5 nmol/mol were developed in order to establish primary national standards of VOCs in HAPs at ambient levels. Primary reference gas mixtures (PRMs) were prepared in pressurized aluminum cylinders with special internal surface treatment using gravimetric method. Analytical methods using gas chromatography-flame ionization detector (GC-FID) coupled with a cryogenic preconcentrator were also developed to verify the consistency of gravimetrically prepared HAP VOCs PRMs. Three different columns installed in the GC-FID were evaluated and compared for the retention times and separation of eighteen target components in a chromatogram. Results show that the HAP VOCs PRMs at 5 nmol/mol were consistent within a relative expanded uncertainty (k=2) of less than 3 % except acrylonitrile (less than 6 %) and the 18 VOCs were stable for 1 year within their associated uncertainties.

• Journal of Korean Society for Atmospheric Environment
• /
• v.30 no.1
• /
• pp.77-87
• /
• 2014

In this study, an experimental approach to measure a suite of low weight hydrocarbons was investigated with an emphasis on ethylene (EL) along with many others (ethane (EA), propane (PA), propylene (PL), n-butane (BA), acetylene (AL), methyl acetylene (ML)). Their concentrations were quantified using GC-FID system equipped with thermal desorption (TD) system. The TD-based analysis was conducted using both Link Tube/Thermal Desorber (LT/TD) method and Modified Injection through a Thermal Desorption (MITD) method. The results of these analyses were evaluated in a number of respects. The system allowed the detection of all compounds except methane with the mean response factor (RF) of 10.28 (EA) to 11.94 (PL). The method detection limits of target compounds were seen in the range of 0.027 (ML) to 0.146 ng (BA). The emission flux of some environmental samples (fruits), when measured using a small flux chamber system, fell in the range of 0.14 (AL: Kiwi) to $181ng{\cdot}g^{-1}{\cdot}hr^{-1}$ (EL: Apple Peel). The results of this study confirm that the experimental approach developed in this study allows to accurately measure emissions of low weight hydrocarbons (LWHC) like ethylene from various natural and man-made source processes.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.16 no.3
• /
• pp.222-232
• /
• 2006

Objectives: The objective of this study was to propose the total isocyanate analytical method which involves derivation of 2,4-toluene diisocyanate(2,4-TDI), 2,6-toluene diisocyanate(2,6-TDI), 4,4'-methylenediphenyl diisocyanate(4,4'-MDI) and 1,6-hexamethylene diisocyanate(1,6-HDI) using 2-chlorobenzyl alcohol(2-CBA) or 2,4-dichlorobenzyl alcohol(2,4-DCBA), and analyzing of hydrolysate of the synthesized urethane with the gas chromatography(GC)/flame ionization detector(FID), GC/pulsed discharge ionization detector-electron capture detector(PD-ECD) and GC/mass selective detector(MSD). Methods: Urethanes were synthesized by reacting 2,4-TDI, 2,6-TDI, 4,4'-MDI and 1,6-HDI to 2-CBA or 2,4-DCBA. Urethanes was verified by TLC, HPLC/UVD and GC/MSD. For field application, the most suitable condition that 2-CBA coated in glass fiber filter removed completely and urethanes were not removed was searched. 2-CBA generated from hydrolysis of urethanes according to hydrolysis conditions. Diisocyanates were collected on field air and analyzed. Results: Urethanes which were white and solid phase synthesized by reacting 2,4-TDI, 2,6-TDI, 4,4'-MDI, 1,6-HDI and 2-CBA or 2,4-DCBA. And urethanes were verified by TLC, HPLC/UVD and GC/MSD. The most suitable conditions to remove 2-CBA coated in glass fiber filter were $87^{\circ}C$ and 20 mmHg and urethanes were not removed under same condition. Hydrolysis yields of urethanes were 99 % to 111 %. 2-CBA, the hydrolysate of urethanes was analyzed by GC/FID, GC/PD-ECD and GC/MSD. Conclusions: Simultaneous analysis of 2,4-TDI, 2,6-TDI, 4,4'-MDI and 1,6-HDI deriving with 2-CBA and 2,4-DCBA, along with a total isocyanate analysis, was feasible with GC/FID, GC/PD-ECD and GC/MSD. This result will be a guide of further study on total isocyanate analysis.

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

• Journal of Food Hygiene and Safety
• /
• v.36 no.1
• /
• pp.34-41
• /
• 2021

The purpose of this research is to improve analysis methods of determining the contents of fatty acids in infant formulas and follow-up formulas. A gas chromatography (GC) method was performed on a GC system coupled to flame ionization detector, with a fused silica capillary column (SP2560, 100 m×0.25 mm, 0.20 ㎛). The method was validated using standard reference material (SRM, NIST 1849a). Performance parameters for method validation such as specificity, linearity, limits of detection (LOD) and quantification (LOQ), accuracy and precision were examined. The linearity of standard solution with correlation coefficient was higher than 0.999 in the range of 0.1-5 mg/mL. The LOD and LOQ were 0.01-0.06 mg/mL and 0.03-0.2 mg/mL, respectively. The recovery using standard reference material was confirmed and the precision was found to be between 0.8% and 2.9% relative standard deviation (RSD). Optimized methods were applied in sample analysis to verify the reliability. All the tested products had acceptable contents of fatty acids compared with component specification for nutrition labeling. The result of this research will provide efficient experimental information and strengthen the management of nutrients in infant formula and follow-up formula.

• The Korean Journal of Food And Nutrition
• /
• v.34 no.2
• /
• pp.217-223
• /
• 2021

Vegetable oils are a rich source of bioactive substances. Phytosterols in those have been known for many years for their properties for reducing blood cholesterol levels, as well as their other beneficial health effects. Phytosterols are triterpenes that are important structural components of plant cell membranes just as cholesterol does in animal cell membranes. The aim of this study was to provide consumers with information about phytosterol contents in vegetable oils in Korea market. The contents of major phytosterols (campesterol, stigmasterol, β-sitosterol) in 50 vegetable oils of 10 kinds (perilla oil, peanut oil, avocado oil, olive oil, pine nut oil, sesame oil, canola oil, coconut oil, grape seed oil, and sunflower oil) were analyzed by gas chromatography with flame ionization detector. The average contents of vegetable oils containing 5 or more samples were in the order of sesame oil (334.43 mg/100 g), perilla oil (262.16 mg/100 g), grape seed oil (183.71 mg/100 g), and olive oil (68.68 mg/100 g). Phytosterol content of sesame oil and perilla oil was high among vegetable oils.