• Journal of Food Hygiene and Safety
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• v.30 no.1
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• pp.81-86
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• 2015

The purpose of our paper was to investigate the migration level of 4,4'-MDA(4,4'-methylenedianiline), 2,4-TDA(2,4-toluenediamine), aniline, acrylonitrile and methylmeth acrylate from plastic cookwares into food simulants and to evaluate the safety of each monomers. The test articles for monomers were PA (polyamide) items for 4,4'-MDA, 2,4-TDA and aniline, PU (polyurethane) items for 4,4'-MDA, ABS (acrylonitrile-butadiene- styrene) items for acrylonitrile, and acrylic resin items for methylmethacrylate. All the article samples of 321 intended for contact with foods were purchased in domestic market. 4,4'-MDA, 2,4-TDA and aniline were analyzed by LC-MS/MS (liquid chromatography -tandem mass spectrometer), acrylonitrile by GC-NPD (gas chromatography-nitrogen phos phorus detector) and methyl methacrylate by GC-FID (gas chromatography-flame ionization detector). The migration level of monomers were within the migration limits of Ministry of Food and Drug Safety (MFDS). As a result of safety evaluation, our results showed that the estimated daily intake (EDI, mg/kg bw/day)s were $2.39{\times}10^{-9}$ and $1.20{\times}10^{-9}$ for 4,4'-MDA and 2,4-TDA of PA, $4.32{\times}10^{-9}$ for acrylonitrile of ABS and $2.27{\times}10^{-7}$ for methylmethacrylate of acrylic resin. Reference Dose (RfD, mg/kg bw/day) of acrylonitrile and tolerable daily intake (TDI, mg/kg bw/day) of methacrylate were established respectively as 0.001 by EPA (US Environmental Protection Agency) and as 1.2 by WHO (World Health Organization). When comparing with RfD and TDI, the EDIs of acrylonitrile and methylmethacrylate accounted for $4.32{\times}10^{-4}%$ and $1.89{\times}10^{-5}%$ respectively.

• Journal of Food Hygiene and Safety
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• v.32 no.1
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• pp.57-63
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• 2017

Foreign materials with a variety of types and sizes are found in food; thus, extraordinary efforts and various analytical methods are required to identify the types of foreign materials and to find out accurate causes of how they unintentionally enter food. In this study, human, cow, pig, mouse, duck, goose, dog, and cat were chosen as various types of animal hairs because they can be frequently incorporated into food during its production or consumption step. We morphologically analyzed them using stereoscopic, optical, SUMP method, and scanning electron microscopes, showing differences in each type. In addition, X-ray fluorescence spectrometer (XRF) was used to analysis chemical compositions ($^{11}Na{\sim}^{92}U$, Mass%) of samples. As a result, we observed that mammalian hairs were mainly composed of sulfur. Organic compounds of samples were further analyzed by fourier transform infrared spectroscopy (FT-IR) that can compare spectra of given materials; however, this method did not show significant differences in each sample. In this study, we suggest a rapid method for the identification of the causes and types of foreign materials in food.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.183-187
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• 2004

Radioactivity in foodstuffs was surveyed for reference in amending regulation on the maximum permitted levels of radioactive contamination of foodstuffs. Most domestic and imported (?) foodstuffs were sampled, some domestic items collected around nuclear power plants to compare site-specific contamination. The collected samples were dried and ashed. Radioactivity in foodstuffs was measured using HPGe gamma spectrometer, Cs-137 activity ranged from 0.025-0.053, 0.045-0.500, 0.062-0.105, 0.025-1.151, 0.021-0.145 and 0.046-0.155 Bq/kg-fresh in cereals, pulses, mot vegetables (potato), ginsengs, meat, and marine products, respectively, with imported dried ginseng showing the highest radioactivity, Results reveal radioactivity in foodstuffs collected in 2002 is far below the maximum permitted levels of 370 Bq/kg. No significant differences were observed in radioactivity among sampling sites and between domestic and imported foodstuffs.

• Korean Journal of Food Science and Technology
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• v.49 no.6
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• pp.649-658
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• 2017

The potential of the ethyl acetate fraction from Pteridium aquilinum (EFPA) to improve the cognitive function in high-fat diet (HFD)-induced diabetic mice was investigated. EFPA-treatment resulted in a significant improvement in the spatial, learning, and memory abilities compared to the HFD group in behavioral tests, including the Y-maze, passive avoidance, and Morris water maze. The diabetic symptoms of the EFPA-treated groups, such as fasting glucose and glucose tolerance, were alleviated. The administration of EFPA reduced the acetylcholinesterase (AChE) activity and malondialdehyde (MDA) content in mice brains, but increased the acetylcholine (ACh) and superoxide dismutase (SOD) levels. Finally, kaempferol-3-o-glucoside, a major physiological component of EFPA, was identified by using high-performance liquid chromatography coupled with a hybrid triple quadrupole-linear ion trap mass spectrometer (QTRAP LC-MS/MS).

• Analytical Science and Technology
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• v.29 no.2
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• pp.94-103
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• 2016

An analytical method was developed to determine the amount of spinetoram (spinetoram J and spinetoram L) in livestock samples. The spinetoram was extracted with acetonitrile and purified through a primary secondary amine (PSA) sorbent. The spinetoram residues were then quantified and confirmed using a liquid chromatography–tandem mass spectrometer (LC-MS/MS) in the positive ion mode using multiple reactions monitoring (MRM). Matrix-matched calibration curves were linear over the calibration ranges (0.005-0.5 mg/kg) into a blank extract with r² > 0.994. The limits of detection and quantification were 0.002 and 0.01 mg/kg, respectively. The recovery results of spinetram ranged between 81.9-106.4% at different concentration levels (LOQ, 10LOQ, 50LOQ, n=5) with relative standard deviations (RSDs) less than 10%. All values were consistent with the criteria ranges requested in the Codex guidelines (CAC/GL40, 2003). An interlaboratory study was conducted to validate the method. The proposed analytical method proved to be accurate, effective, and sensitive for spinetoram determination. The method will be used as an official analytical method in Korea.

• Analytical Science and Technology
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• v.26 no.4
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• pp.287-297
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• 2013

The optimization of analytical method for the thermal desorption of seven VOCs (volatile organic compounds) by TD-GC/MS (thermal desorption-gas chromatograph-mass spectrometer) with solid phase sorbent tube, and comparative analysis for the determination of VOCs plotted by standard sorbent tubes prepared using both gas phase and liquid phase materials were investigated. The result of paired t-test showed that a liquid phase standard sorbent tube method was in agreement with a gas phase standard sorbent tube method for six species of VOCs including benzene, toluene, ethylbenzene, o-, m-, and p-xylene except for styrene at the significance level (${\alpha}=0.01$), while the 15.6% of difference in response factor between both of gas phase and liquid phase standard plotting for the determination of styrene showed that both methods were significantly different at the significance level. Therefore, the liquid phase standard plotting method was employed to reduce erroneous data for the determination of styrene including BTEX. Under the optimized analytical method by liquid phase standard sorbent tube, recovery was between $100{\pm}5%$ for 7 species of VOCs, reproducibility ranged from 0.3 to 7.7%, and method detection limit (MDL) ranged from $0.01{\mu}g/m^3$ for o-xylene to $0.27{\mu}g/m^3$ for toluene. The optimized standard method was applied to determine VOCs VOCs from indoor air of of dormitory, one bedroom apartment, and a new car.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.93-103
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• 2016

A simultaneous analytical method was developed for the determination of isoxaflutole and metabolite (diketonitrile) in agricultural commodities. Samples were extracted with 0.1% acetic acid in water/acetonitrile (2/8, v/v) and partitioned with dichloromethane to remove the interference obtained from sample extracts, adjusting pH to 2 by 1 N hydrochloric acid. The analytes were quantified and confirmed via liquid chromatograph-tandem mass spectrometer (LC-MS/MS) in positive-ion mode using multiple reaction monitoring (MRM). Matrix matched calibration curves were linear over the calibration ranges ($0.02-2.0{\mu}g/mL$) for all the analytes into blank extract with $r^2$ > 0.997. For validation purposes, recovery studies were carried out at three different concentration levels (LOQ, 10LOQ, and 50LOQ) performing five replicates at each level. The recoveries were ranged between 72.9 to 107.3%, with relative standard deviations (RSDs) less than 10% for all analytes. All values were consistent with the criteria ranges requested in the Codex guideline (CAC/GL40, 2003). Furthermore, inter-laboratory study was conducted to validate the method. The proposed analytical method was accurate, effective, and sensitive for isoxaflutole and diketonitrile determination in agricultural commodities.

• The Journal of Korean Society for Radiation Therapy
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• v.17 no.2
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• pp.87-94
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• 2005

Purpose : Heavy metal use when producing the block from the workshop. At this time, production of heavy metal dust and fume gives risk in human. This like heavy metal to improve seriousness through measurement and analysis. And by the quest in solution is purpose of this thesis. Materials and Methods : Organization is Inductively Coupled Plasma Atomic Emission Spectrometer, and the object is Deajeon city 4 workshops in university hospital radiation oncology (Bismuth, Lead, Tin and cadmium). Method is the ppb the pumping it does at unit, comparison analysis. And the Calculation heavy metal standard level in air through heavy metal standard level in body and blood, so Heavy metal temporary standard set. Results : Subterranean existence room air quality the administration laws appointed Lead and Cadmium's exposure recommend that it is $3{\mu}g/m^3\;and\;2{\mu}g/m^3$. And Bismuth and Tin decides $7{\mu}g/m^3\;and\;6{\mu}g/m^3$ through standard level in air heavy metal and standard level in body and blood. Heavy metal measurement level of workshops in 4 university hospital Daejeon city compares with work existence and nonexistence. On work nonexistence almost measurement level is below the recommend level. But work existence case express high level. Also consequently in composition ratio of the block is continuous with the detection ratio. Conclusion : Worker's heavy metal contamination imbrued serious for solution founds basic part. In hospital may operation on local air exhauster and periodical efficiency check, protector offer, et al. And worker have a correct understanding part of heavy metal contamination, and have continuous interest, health control. Finally, learned society sphere administer to establishment standard level and periodical measurement. And it founds basic solution plan of periodical special health checkup.

• Journal of Soil and Groundwater Environment
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• v.7 no.2
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• pp.63-71
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• 2002

The authors selected the modified soil method, and then performed the geotechnical and environmental laboratory test, and evaluated whether the modified soil liner could be accepted as a barrier layer in landfill. Unlike the results of the natural soil(CL), those of the hydraulic conductivity test of stabilized soil met the standard value. According to these results, the optimal mixing ratio of a mixture(cement : bentonite : stabilizing agent) was 90 : 60 : 1 with mass ratio(kg) for 1㎥ with soil, and it was possible to use poor quality bentonite. B\circled2 because of a little difference from results with high quality bentonite. B\circled1. The Cation Exchange Capacity(CEC) of the modified soil was increased about 1.5 times compared with the natural soil; however. the change of CEC with a sort of additives was not detected. In order to observe the change of the chemical components and crystal structures, the natural and the modified soils with the sorts of additives were measured by the XRF(X-Ray Flourescence Spectrometer) and SEM, but there was no significant change. The artificial leachate with the heavy meals ($Pb^{2+}$ , $Cu^{2+}$, $Cd^{2+}$ Zn$^{2+}$ 100mg/L) was passed through the natural soil and modified soils in columns. In the natural soil, Cd$^{2+}$ and $Zn^{2+}$ were identified, simultaneously the pH of outflow was lower, and then came to the breakthrough point. The removal efficiency of the natural soil was showed in order of following : $Pb^{2+}$ ≒$Cu^{2+}$ > $Zn^{2+}$ > $Cd^{2+}$ On the other hand, modified soils were not showed the breakthrough condition like the result of the natural soil. The modified soil with the lower quality bentonite, B\circled2(column3) was more stable with respect to chemical attack than that with the higher bentonite, B\circled1(column2) because the change range of outflow pH in columns was less than that of outflow pH in column2. In addition, the case of adding the stabilizing agent(column4) was markedly showed the phenomena.ena.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.4
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• pp.526-534
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• 2010

The prevalence rate for chronic diseases such as obesity, diabetes, hypertension etc. caused by the increment of national income and the change of food life according to the globalization in Korea have been increased. Especially excess sodium intake may contribute to the development of hypertension, increasing cardiovascular disease risk. The objective of this study was to investigate sodium intake of nursery school meals in Gyeonggi-Do, and to construct database for lesser sodium intake policy. Survey consisted of 601 sample intakes of sodium in summer and in winter. A food weighed record method was used for measuring food intakes. Average intakes of ten children per nursery school were measured. The sodium contents of meals were analyzed by ICP-OES (inductively coupled plasma-optical emission spectrometer) after acid digestion by microwave. The sodium contents on food groups showed that sources (693 mg/100 g), grilled foods (689 mg/100 g) and kimchies (643 mg/100 g) had respectively higher sodium contents and the average sodium intake per meal was $582\pm204$ mg. The sodium contents of soups & hot soups and kimchies had 37.5% and 15.8% of total sodium intakes per meal, respectively. Sodium intakes per meal in summer and winter showed 572.3 mg and 592.3 mg, respectively. Regional ranking of sodium intakes showed the ascending order of apartment (514.3 mg/meal), rural region (540.5 mg/meal), multiplex house (635.9 mg/meal) and industrial complex (696.4 mg/ meal). A habit of excessive sodium intakes in childhood will threaten their health when they grow up to be adults; thus lesser intake of sodium per meal is needed for children in nursery school.