• Journal of Life Science
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• v.20 no.1
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• pp.60-65
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• 2010

Since organic sulfur compounds respond to GC/ECD sensitively, they interfere with quantitative separation of pesticides during residual pesticide analysis of Allium species. In this study, it was intended to develop a rapid and simple method for pesticide multi-residues analysis through clean-up and interferences by a solid-phase extraction (SPE). An SPE method employing silver nitrate impregnated Florosil cartridge was developed and evaluated for the elimination of sulfur compounds from the test solution of Allium species during pesticide residues analysis. The silver nitrate impregnated Florosil cartridge was prepared by efflux of 3 ml of 20% silver nitrate solution through Florosil cartridge (1 g packing, 6 ml tube). The extracts equivalent to 2, 4 6, and 10 g of each sample were loaded onto the cartridge and allowed to exude, and then the exudations were analyzed by GC/ECD. More than 95% of sulfur compounds were removed from the loaded extracts equivalent, up to 6 g in onion, 4 g in spring onion and 4 g in shallot, respectively. 40 pesticides were spiked in the Allium species and loaded onto the cartridge to determine the recoveries; from this, the recoveries of 34 pesticides were within 70~120%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.948-952
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• 2005

The antioxidative and antimicrobial properties of the solvent extracts of 3 parts (leaf, stem, root) of Crotalaria sessiflora L. were investigated, in order to find out new natural food additives. The antioxidative activities of the extracts were determined by peroxide value (POV) and the conjugated diene value (CDV) of corn oil stored for 30 days at $60\pm2^{\circ}C$. Each part of the extracts were added as $0.02,\;0.05\%$ and then compared with BHT. The anti oxidative activities were as follows in decreasing order: BHT > LeafEX > StemEX > RootEX > control. The induction period showed that the part of the Crotalaria sessifloria L. group added with solvent extract showed a longer induction period compared with the control group. The part of Crotalaria sessiflora L. solvent extract were shown to have antimicrobial effects on the microorganism such as Bacillus subtilis, Staphylococcus aureus, Listeria monocytogenes, Salmonella Enteritidis, Pseudomonas flrourescens and Escherichia coli. Especially the effect on the Pseudomonas flrourescens was remarkable.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1318-1322
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• 2008

The aim of this study was to analyze the antioxidant properties of Lycii folium extracts prepared from different solvents. Lycii folium were extracted with water, 80% ethanol (80% EtOH), 80% methanol (80% MeOH) and 100% methanol (100% MeOH) in water bath at $40^{\circ}C$. The antioxidant activity of the extracts was evaluated using DPPH, hydroxyl and hydrogen radical scavenging activities, and SOD-liked activity. Total phenolic acid contents were 1.085 mg/mL in 100% MeOH, 1.382 mg/mL in 80% EtOH, 1.420 mg/mL in 80% MeOH and 1.084 mg/mL in water. DPPH radical scavenging activity of the extracts were 65.60% in 80% EtOH, 56.80% in 80% MeOH, 83.85% in 100% MeOH and 54.65% in water. Hydroxyl radical scavenging activities were 66.65% in 100% MeOH, 73.13% in 80% ethanol, 73.58% in 80% MeOH and 70.73% in water. Hydrogen radical scavenging activity of the extracts prepared from Lycii folium were 11.70% in 100% MeOH, 33.73% in 80% EtOH, 35.40% in 80% M eOH and 23.86% in water. SOD-liked activity of the extracts prepared from Lycii folium was 71.58% in 100% MeOH, 74.29% in 80% EtOH, 88.46% in 80% MeOH and 67.47% in water. Our result showed that Lycii folium extracts prepared from 80% methanol were found to be promising biomaterials with antioxidant effects.

• Analytical Science and Technology
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• v.28 no.2
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• pp.125-131
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• 2015

A method was developed and fully validated for the determination of terbutaline, a β₂-receptor agonist, in human plasma. Plasma samples were prepared by solid-phase extraction with Sep-Pak silica, followed by high-performance liquid chromatography (HPLC). The terbutaline was pre-separated from the interfering components in plasma on a Luna C18 (2) column, and terbutaline and salbutamol as an internal standard were resolved and determined on a Luna Silica column. The two columns were connected by a switching valve equipped with silica pre-column. The pre-column was used to concentrate the terbutaline in the eluent from the C18 column before back-flushing onto the silica column with fluorescence detection at an excitation/emission wavelength of 276/306 nm. The method was shown to be specific by testing six different human plasma sources. Linearity was established for a concentration range of 0.4-20.0 ng/mL with a correlation coefficient of 0.9999. The lower limit of quantitation was 0.4 ng/mL with a precision of 10.1% as C.V.%.

• 한국약용작물학회:학술대회논문집
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• 2008.05a
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• pp.184-185
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• 2008

• Advanced Industrial SCIence
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• v.2 no.3
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• pp.29-36
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• 2023

The purpose of this study is to present basic data for hair color work plans that can consistently produce hair color design products for designers through analysis of gradient techniques among hair color design techniques. The research method was to select 10 photos of women that appeared in mass media from 2022 to September 15, 2023, extract color chips and RGB values using the Eyedropper Tool in Adobe Photoshop CS6, and convert the RGB values of the color chips into Munsell Conversion ( The data was converted into HV/C values of version 12.1.13a). Based on the extracted data, the gradient hair colors of female pop stars were analyzed by displaying the data on a color scale. As a result, in the I.R.I color scheme image scale, the image of female pop stars was more hard than soft. In addition, it was confirmed that the focus was on static rather than dynamic. Color matching images according to hair color were extracted with adjectives such as noble, decent, elegant, and subtle. Three hairstyles were created using this theme.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.2
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• pp.158-164
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• 2006

Offensive odor from CAFO(concentrated animal feeding operation) and its control have become a significant issue in Korea. Control of odors from the CAFO requires to identify major odorant and their generation mechanisms. In this study, an easy method to collect gas sample and to quantify its odorants is proposed. The method involves on-site odorant extraction with solid-phase microextraction and quantitation with GC/MSD or GC/FID. Analytes of the current study include: trimethylamine(TMA), carbon disulfide($CS_2$), dimethyl sulfide(DMS), dimethyl disulfide(DMDS), acetic acid(AA), propionic acid(PA) and n-butyric acid(BA). The resulting linearity($R^2$) of calibration curve for each analyte was good over the range from several ppbv to ppmv; 0.984 for TMA(0.056-1.437), 0.996 for $CS_2$(0.039-0.999), 0.994 for DMS(0.029-0.756), 0.995 for DMDS(0.024-0.623), 0.992 for AA(0.068-1.314), 0.955 for PA(0.047-0.940), and 0.976 for BA(0.036-0.712). Method detection limits were 5.67, 6.39, 5.78, 25.2, 0.098, 0.363 and 0.099 ppbv for AA, PA, BA, TMA, DMS, $CS_2$, and DMDS, respectively. With the developed method, odorants from poultry, swine, and cattle barns were analysed. All the compounds but DMDS were detected from the sample collected in the poultry barn, and their levels exceeded the representative published human olfactory threshold.

• Analytical Science and Technology
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• v.25 no.6
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• pp.460-466
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• 2012

An environmentally friendly, so-called green, high performance liquid chromatography method was developed and validated for the determination of trans, trans-muconic acid (t,t-MA) in human urine as a biomarker of benzene exposure. After urinary t,t-MA was extracted and enriched using solid-phase extraction, a MF-Ph1 SG80 ($150mm{\times}2.0mm$ I.D., 5 ${\mu}m$) column with a mobile phase of 10 mM $KH_2PO_4$ containing 0.1% $H_3PO_4$ was used for isocratic separation of t,t-MA with UV detection at 259 nm. The calibration curve was constructed in the range of 0.1-5.0 mg/L with good linearity ($r^2$=0.9992). The intra-day and inter-day precision (as RSD) were 0.9-8.5% and 3.1-4.5%, respectively. The average recovery ranged from 97.5% to 101.7%. The green sample preparation and separation with no organic solvents were successfully achieved. The validated method would be suitable for the routine biological monitoring of benzene exposure in the occupational settings.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.11
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• pp.764-770
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• 2014

This study assessed analysis of N-nitrosamines by separation, identification, and quantification using a gas chromatography (GC) mass spectrometer (MS) with electron impact (EI) mode. Samples were pretreated by a automated solid phase extraction (SPE) and a nitrogen concentration technique to detect low concentration ranges. The analysis results by EI-GC/MS (SIM) and EI-GC/MS/MS (MRM) on standard samples with no pretreatment exhibited similar results. On the other hand, the analysis of pretreated samples at low concentrations (i.e. ng/L levels) were not reliable with a EI-GC/MS due to the interferences from impurity peaks. The method detection limits of eight (8) N-nitrosamines by EI-GC/MS/MS analysis ranged from 0.76 to 2.09 ng/L, and the limits of quantification ranged from 2.41 to 6.65 ng/L. The precision and accuracy of the method were evaluated using spiked samples at concentrations of 10, 20 and 100 ng/L. The precision were 1.2~13.6%, and the accuracy were 80.4~121.8%. The $R^2$ of the calibration curves were greater than 0.999. The recovery rates for various environmental samples were evaluated with a surrogate material (NDPA-$d_{14}$) and ranged 86.2~122.3%. Thus, this method can be used to determine low (ng/L) levels of N-nitrosamines in water samples.

• Analytical Science and Technology
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• v.25 no.4
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• pp.236-241
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• 2012

There are many industrial factories in the central Nakdong river basin and have been occurred water pollution accidents by hazardous chemicals such as phenol, 1,4-dioxane and perchlorate. In this study, ten compounds of semi-volatile organic compounds (SVOCs) (dichlorvos, toluene-2,4-diisocyanate, 4,4'-methylenedianiline, 4,4'-methylenebis (2-chloroaniline), diethyl phthalate, di-n-butyl phthalate, butyl benzyl phthaltate, bis (2-ethylhexyl) adipate, benzophenone, 4,4'-bisphenol A) of hazardous chemicals which may be potentially discharged into the Nakdong river, were determined by gas chromatography-mass spectrometry (GC-MS) with disk-type solid-phase extraction. Accuracy and precision were in the range of 75.6~110.5%, and 4.6~12.7%, respectively and recovery was in the range of 72.4~127.9%. Three compounds (bis (2-ethylhexyl)adipate, benzophenone, 4,4'-bisphenol A) were detected in industrial wastewater such as wastewater treatment plants (WWTPs) and wastewater discharge facilities in the Nakdong River basin.