• Food Science of Animal Resources
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• v.33 no.5
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• pp.640-645
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• 2013

The purpose of this study was to utilize the results as a basic data of benzoic acids in animal products that didn't mention in the quality standard of National Veterinary Research and Quarantine Service (NVRQS) to solve the conflict of international trade and administration. Set-Pak method listed in the quality standard of NVRQS, faster than auto distillation methods with same recovery selected as a pre treatment for the determination of benzoic acid. The regression curve of benzoic acid with Sep-Pak method was linear with the $R^2$ value of 0.999 and the limit of detection (LOD) and limit of quantitation (LOQ) was 0.058 mg/kg and 0.176 mg/kg, respectively. The benzoic acid in the fermented milk was detected after the fermentation stage by addition of starter culture with the level of 2.28~10.48 mg/kg and 0~16.5 mg/kg in the commercial fermented milk products without detection by the addition of syrup. In case of cheese products, the benzoic acids level was influenced by the curd formation (Camembert cheese) and the quality of natural cheese (processed cheese), by the way, the benzoic acid level of commercial natural cheese was 0~4.2 mg/kg, processed cheese was 0~20.8 mg/kg, respectively. Based on this result, it may be possible to utilize as a basic data for the systematic control the level of natural benzoic acids in raw material, processing and final products of animal origin.

• Food Science of Animal Resources
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• v.33 no.5
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• pp.655-663
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• 2013

In this study, a rapid and sensitive detection tool for screening Salmonella spp. by using a loop-mediated isothermal amplification (LAMP) assay targeting the genomic sequence of the invA gene was developed. The inclusivity and exclusivity were both at 100% in the analysis, and the limit of detection (LOD) in a pure S. Enteritidis culture suspended in saline was $3.2{\times}10^3$ CFU/mL at 18.17 min ($R^2$ = 0.9446). The LODs of the LAMP assay in buffered peptone water with Salmonella (BPW) and duck carcass swab sample enriched in BPW with Salmonella (BPWS) after 0 and 12 h incubation were $3.2{\times}10^3$ CFU/mL and $3.2{\times}10^0$ CFU/mL, respectively. Comparing the LODs in BPW with those in BPWS, the LAMP assay was less influenced by compounds of duck carcass swab sample than the PCR assay. Sensitivity and specificity of the LAMP assay in 50 duck carcass swab samples enriched in BPW for 6 h were 96% and 84%, respectively, indicating that the LAMP assay is a rapid, simple and sensitive assay, which can be utilized as a potential screening tool of Salmonella spp. in duck carcass sample.

• Herbal Formula Science
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• v.21 no.2
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• pp.133-143
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• 2013

Objectives : We carry out the simultaneous quantification for quality control of four components in Bangpungtongseong-san (BPTSS) sample. In addition, we assessed the antioxidant effects of BPTSS sample. Methods : The used column for separation and analysis of four compounds was Luna C18 column and column oven temperature was maintained at $40^{\circ}C$. The mobile phase for simultaneous determination consisted of two solvent systems, 1.0% acetic acid in water and 1.0% acetic acid in acetonitrile. High performance liquid chromatography-photodiode array (HPLC-PDA) method for analysis was performed at a flow rate of 1.0 mL/min with PDA detection at 254 and 280 nm. The injection volume was 10 ${\mu}L$. The antioxidant activities of BPTSS were evaluated by measuring free radical scavenging activities on 2,2'-Azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) and 1-1-diphenyl-2-picrylhydrazyl (DPPH). The inhibitory effects on low-density lipoprotein (LDL) oxidation were evaluated by the formation of thiobarbituric acid relative substances (TBARS) and relative electrophoretic mobility (REM). Results : Calibration curves were acquired with $r^2{\geq}0.9999$. The values of limit of detection (LOD) and quantification (LOQ) were 0.06-0.29 ${\mu}g/mL$ and 0.20-0.98 ${\mu}g/mL$, respectively. The amounts of geniposide, liquiritin, baicalin, and glycyrrhizin in BPTSS were 5.06, 7.33, 27.56, and 7.81 mg/g, respectively. The BPTSS showed the radical scavenging activity in a dose-dependent manner. The concentration required for 50% reduction (RC50) against ABTS and DPPH radicals were 72.51 ${\mu}g/mL$ and 128.49 ${\mu}g/mL$. Furthermore, GMGHT reduced the oxidation properties of LDL induced by CuSO4. Conclusions : The established HPLC-PDA method will be helpful to improve quality control of BPTSS. In addition, BPTSS has potentials as therapeutic agent on anti-atherosclerosis.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.3
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• pp.393-405
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• 2018

Volatile organic compounds (VOCs) are representative air pollutants due to their detrimental effects on human health and their role in formation of secondary organic aerosols. Assessments and monitoring programs of VOCs using periodic grab sampling like Tedlar bags, canisters, and sorbent traps provide limited information, often with delay times of days or weeks. Selected ion flow tube mass spectrometry (SIFT-MS) is an emerging analytical technique for the real-time quantification of VOCs in air. It relies on chemical ionization of the VOCs molecules in air introduced into helium carrier gas using $H_3O^+$, $NO^+$, and $O_2{^+}$ precursor ions. Real-time monitoring method of 60 VOCs in the ambient air was developed using TO-15 standard gas mixture. Calibration curves, method detection limit, and quantitation reproducibility of the target compounds were tested. Dynamic dilution system was used to dilute standard gas from 0.174 ppbv to 100 ppbv, where calibration curves showed good linearity with $r^2$> 0.95 in all target analytes. Limit of detection (LOD) all compounds were sub ppbv, and some halogenated compounds showed pptv levels. Seven consecutive analyses of target compounds showed good repeatability with relative standard deviation of less than 10%. One day monitoring of VOCs in ambient air was conducted in Geoje. Average concentration of target VOCs in Geoje were relatively lower than other regions, among which formaldehyde showed the highest concentration ($15.4{\pm}5.78ppbv$). SIFT-MS provided good temporal resolution data (1 data per 3.2 minute), which can be used for identifying ephemeral short-term event. It is expected that SIFT-MS will be a versatile monitoring platform for VOCs in ambient air.

• Korean Journal of Remote Sensing
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• v.27 no.1
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• pp.33-41
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• 2011

In the information communication technology, it is world-widely apparent that trend movement from internet web to smartphone app by users demand and developers environment. So it needs kinds of appropriate technological responses from geo-spatial domain regarding this trend. However, most cases in the smartphone app are the map service and location recognition service, and uses of geo-spatial contents are somewhat on the limited level or on the prototype developing stage. In this study, app for extraction of corner point features using geo-spatial imagery and their linkage to database system are developed. Corner extraction is based on Harris algorithm, and all processing modules in database server, application server, and client interface composing app are designed and implemented based on open source. Extracted corner points are applied LOD(Level of Details) process to optimize on display panel. Additional useful function is provided that geo-spatial imagery can be superimposed with the digital map in the same area. It is expected that this app can be utilized to automatic establishment of POI (Point of Interests) or point-based land change detection purposes.

• Journal of Food Hygiene and Safety
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• v.22 no.4
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• pp.370-374
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• 2007

An analytical method for the simultaneous determination of four tetracycline (oxytetracycline, tetracycline, chlortetracycline, doxycycline) in egg samples was developed and validated using liquid chromatography with ultraviolet detection. Egg samples were extracted by the liquid-liquid extraction based on acetonitrile. The chromatographic separation was achieved on a reverse phase C8 column with gradient elution using a mobile phase of 20 mM oxalic acid (pH 1.5)/acetonitrile. The procedure was validated according to the Food Drugs Administration guideline determining accuracy, precision, and limit of detection. Mean recovery of tetracyclines from spiked egg samples (50, 100, 200, 400, and $800{\mu}g/kg$) were 78.8-109.3%. Linearity in concentration range of $50-800{\mu}g/kg$ was obtained with the correlation coefficient $(r^2)$ of 0.994-0.999. The intra- and inter-day precision (relative standard deviation; RSD) was between 0.3-12.8 and 0.2-11.7%, respectively. Limit of detection (LOD) and limit of quantification (LOQ) for the investigated tetracyclines were 30 and $50{\mu}g/kg$ depending on egg samples, respectively. This method was reliable, sensitive, economical and suitable for routine monitoring of tetracycline residues in dairy egg.

• Journal of Food Hygiene and Safety
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• v.23 no.3
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• pp.218-221
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• 2008

The levels of sulfites in wooden chopsticks were analyzed using two different methods, distillation-alkali titration and ion chromatography. According to the two methods, Sulfur dioxide($SO_2$) was validated by 0.6 and 0.2 ${\mu}ml$ of limit of detection(LOD), 1.8 and 0.5 ${\mu}ml$ of limit of quantification, (LOQ) and a $R^2>0.998$ for linearity, respectively. The recoveries of $SO_2$ from food simulants spiked ar levels of 100 ppm were 70.2-100.2%. 158 samples of wooden chopsticks were monitored the migrated amounts of sulfites. Sulfites were detected in 30 samples in ranged of 0.6 to 15.5 ppm. Maximum migration level, 15.5 ppm of sulfites was considered giving no harmful effect to human since it was reached 5.5% of estimated SML.

• Korean Journal of Food Science and Technology
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• v.47 no.5
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• pp.556-560
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• 2015

This study was aimed at investigating the natural occurrence of caffeine, theobromine, and theophylline in tea leaves. Sample clean-up was based on a simple solid phase extraction (SPE) treatment, and simultaneous analysis was performed by high performance liquid chromatography (HPLC). This method showed good results in terms of linearity, recovery, precision, limit of detection (LOD), and limit of quantitation (LOQ). The caffeine, theobromine, and theophylline contents of tea leaves (n = 228) ranged from 5.4 to 58.2 mg/g, from not detected to 11.2 mg/g, and from not detected to 0.7 mg/g, respectively. The results obtained in this study can be used as fundamental data of caffeine, theobromine, and theophylline contents in tea leaves.

• The Korean Journal of Pesticide Science
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• v.13 no.3
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• pp.133-147
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• 2009

In order to develop the simultaneous analytical method for pesticide residues which ones in soil are rapidly and inexpensively measured by, many analytical methods for individual pesticide residue and several methods for multi-pesticide residues in agricultural commodities and food were reviewed. Various gas chromatographic conditions and pre-treatment procedures were intensively investigated and modified. And then new optimum procedure was established and its proficiency was validated. The response on detectors of simultaneous determination of 180 pesticides out of pesticides used in Korea was tested. The number of pesticides that their limits of detection (LOD) equal or lower than $0.05\;mg\;kg^{-1}$ were 137 pesticides on ECD, 170 pesticides on NPD and 179 pesticides on ECD/NPD integrated. The retention times of most pesticides ranged appropriately between 10 minutes and 40 minutes in the proposed chromatographic conditions. But about 90 pesticides eluded between 20 minutes and 30 minutes and so they were not resolved enough. In partition with dichloromethane, ethyl acetate/hexane (1:1) and ethyl acetate, number of pesticides whose extraction efficiency ranged from 70% to 120%, were 163, 154 and 147, respectively.

• Journal of Life Science
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• v.19 no.9
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• pp.1239-1244
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• 2009

This study was conducted to clarify the genetic relationship between Calanthe discolor, C. sieboldii and variants, and the cause of flower color variations by using a molecular linkage map and a quantitative trait loci (QTL) analysis for flower and lip color in Calanthe species native to Korea. Twenty plants were included in three C. discolor and three C. sieboldii, and fourteen variants were obtained from their habitat, Jeju-do in Korea. The flowers of C. discolor were brownish red, the values of Commission Internationale de I'Eclairage (CIE) Lab were between 40 and 50. The flowers of C. sieboldii were yellowish, the values of CIE Lab were between 110 and 130. The variants had various mixed colors that were thought to have originated from natural hybridization between C. discolor and C. sieboldii, and the values of CIE Lab were between 50 and 70. The colors of the lips were usually divided into white and yellow. C. discolor had a white lip, C. sieboldii had a yellow one, and the variants had a white to yellow one. The CIE Lab value of each color was 90 in white and 110 to 120 in yellow lips. A molecular linkage mapping was constructed based on the segregation of 154 RAPD markers using a MAPL program. Sixteen linkage groups containing 66 markers were established. It covered a total map distance of 220.4 cM. The distance between adjacent markers ranged from 0 to 6.6 cM, with an average distance of 3.3 cM. These markers are thought to be closely associated with flower and lip color expression. Among the 16 molecular linkage groups, 3 QTLs had flower color trait loci and 1 QTL had lip color trait loci.