• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.4
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• pp.377-382
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• 1992

This study was conducted to obtain basic informations on the lignan components from sesame seed. Two major lignans, sesamin and sesamolin, were isolated and identified by means of spectral methods, and quantitative analysis was by HPLC from sesame variety Danbaeggae. Separation was achieved by isocratic elution and reversed phase chromatography Develosil ODS column. The content of the major lignan components were about 0.42% and 0.30% for sesamin and sesamolin, respectively.

• Journal of the Korean Chemical Society
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• v.35 no.5
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• pp.539-544
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• 1991

A method to determine the thickness of silicone resin film on zinc eletroplated steel using X-ray compton scattering was investigated. On the basis of the fact that compton scattering process predominates over photoelectric absorption for the light elements such as C, H, O and Si, the compton scattered line of RhK$_{\alpha}$ was used to determine the thickness of silicone resin. In this method, the standard calibration curve for thickness determination of silicone resin film was found to be linear in the range of 0.2~5.0 ${mu}$m film thickness. The analytical results agreed well with those obtained by the gravimetric method and the accuracy was found to be 0.22 ${mu}$m.

• Analytical Science and Technology
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• v.26 no.1
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• pp.80-85
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• 2013

The sixty nine accident preparedness substances (APS) having high probability of chemical accident are controlled under the Toxic Chemicals Control Act (TCCA). Around the world, there has been a growing interest in the analysis of chemical warfare agent (CWAs). When a chemical accident occurs, it is generally required to detect and identify APS. However, the quantitative analytical data remain limited in Korea. In this study, an analytical method using GC/MS for volatile organic chemicals was established and a quantitative analysis method was studied. The calibration curve for 25 chemicals were obtained and 21 chemicals showed higher coefficient of determination ($r^2$ >0.998).

• Analytical Science and Technology
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• v.11 no.1
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• pp.1-7
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• 1998

This study focuses on developing a controlling and analyzing software for the portable atomic emission spectrometer equipped with an electrothermal vaporizer(ETV) that can perform the in-situ trace analysis of heavy metal ions dissolved in water. The software works well for a notebook PC and it is exclusively developed for the real time analysis with a line filter and a photomultiplier light detector. The program is designed to operate under Windows 95 environment and either Korean or English can be used as a main language. The Delphi 2.0 language software is mainly used for programing. The program is designed to make a calibration curve and the system users can get the analytical data in a short time. And a final report can be generated without having difficulties. This software can be easily modified for other analytical atomic spectrometers.

• Analytical Science and Technology
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• v.22 no.4
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• pp.293-301
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• 2009

As a basic research for development of the domestic field-portable XRF spectrometer, we discussed the analytical results of bench-top ED-XRF and field-portable XRF method for polluted heavy metals such as Cr, As, Se, Hg, Pb, Cd in soil samples. To obtain the best performance of the XRF spectrometer, the instrumental parameters of X-ray tube-voltage and measurement time were optimized for 6 heavy-metal elements in soil using certified reference material. The quantitative analysis of Cr, As, Se, Hg, Pb, Cd concentration in certified reference materials and soil samples were compared by empirical method and fundamental parameter method.

• Analytical Science and Technology
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• v.18 no.1
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• pp.43-50
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• 2005

A number of carbonyl compounds including formaldehyde and acetaldehyde are well known for their toxicity and irritancy. Hence, acquisition of both qualitative and quantitative tool for their analysis is essential to resolve issues associated with malodor or indoor pollution. Using HPLC/UV method, we examined various aspects involved in the measurements of formaldehyde in environmental samples. The results of our analysis indicated that its detection was made as low as 0.5 ppb (assuming 5 L of sample volume), while its precision was maintained near 2% in terms of relative standard error (RSE). When the stability of calibration was checked by variability of slope values obtained over long-term period (e.g., one month), its values were found to remain constantly with RSE values of 3%. It was also found that liquid-phase reaction between formaldehyde and DNPH proceed very slowly to attain equilibrium (one and half hour), while requiring adequate amount of DNPH to form their derivatives. The overall results of our study thus suggest that there are a number of factors to consider for the accurate analysis of formaldehyde in ambient air.

• Korean Journal of Plant Resources
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• v.27 no.4
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• pp.286-292
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• 2014

Near infrared reflectance spectroscopy (NIRS) is a rapid and accurate analytical method for determining the composition of agricultural products and feeds. This study was conducted to measure baicalin, baicalein, and wogonin contents in Scutellaria baicalensis by using NIRS system. Total 63 samples previously were analyzed by HPLC, which showed baicalin, baicalein, and wogonin contents ranging 4.56 to 13.59%, 0.28 to 5.54%, and 0.50 to 1.63% with an average of 9.66%, 2.09% and 0.52%, respectively. Each sample was scanned by NIRS and calculated for calibration and validation equation. A calibration equation calculated by modified partial least squares(MPLS) regression technique was developed in which the coefficient of determination for baicalin, baicalein, and wogonin content was 0.958, 0.944, and 0.709, respectively. Each calibration equation was applied to validation set that was performed with the remaining samples not included in the calibration set, which showed high positive correlation both in baicalin and baicalein content file. In case of wogonin, the prediction model was needed more accuracy because of low $R^2$ value in validation set. These results demonstrate that the developed NIRS equation can be practically used as a rapid screening method for quantification of baicalin and baicalein contents in Scutellaria baicalensis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.3
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• pp.549-552
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• 2004

A simple, efficient and accurate method was developed for the simultaneous determination of non-permitted oil soluble colorants (sudan I, II, III and IV) in foods. The identification has been carried out for sudan colorants by TLC as well as HPLC with photodiode array (PDA) detection. Separation of sudan colorants was achieved within 20 min by a gradient elution with water and acetonitrile as eluents. Sudan colorants showed good linear relationships in the range of 0.1 ～ 100 $\mu\textrm{g}$/mL. The correlation coefficients of the calibration curve for sudan colorants exceeded 0.999. The detection limits (signal-to-noise ratio 3 : 1) for sudan I, II, III and IV were 0.01, 0.01, 0.02 and 0.02 $\mu\textrm{g}$/mL, respectively. This method has been successfully applied to the analysis of red pepper powder, Kimchi and Kakdugi, and the average recoveries for real samples ranged from 83.02% to 104.3%.

• Korean Journal of Ecology and Environment
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• v.40 no.2
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• pp.193-200
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• 2007

The objective of this study was to estimate uncertainty of online TOC analyzer in water quality monitoring system. A procedure for the estimation of measurement uncertainty of total organic compounds (TOC) based on the ISO approach is presented. It is based on a mathematical model that involves 4 input parameters (standardization, sensitivity, solute effect and representativeness). In this study, a major problem in estimating the uncertainty of online TOC analyzer was the solute effect. It was strongly depends on organic materials. So homogeneity of the sample is the most important consideration. Modified concentration and combined standard uncertainty was $4.71{\pm}0.36$ mg $L^{-1}$ by model modified in this study.

• Journal of the Korean Wood Science and Technology
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• v.45 no.5
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• pp.572-579
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• 2017

Determination of the wood content in wood plastic composite (WPC) is crucial to form reliable WPC market. WPC with simple formulation consisting of only two components (wood flour and polypropylene) was examined using thermogravimetric analysis (TGA) and accelerator mass spectrometry (AMS) for determining wood content in the WPC. TGA method using derivative peak temperature (DTp) of polypropylene under low heating rate ($5^{\circ}C/min$) showed more reliable calibration curve and lower error factor compared to method of using the percentage of weight loss of wood flour. In addition, AMS using bio-based carbon content showed greater reliability for the determination of wood content in the WPC in comparison with the TGA method.