• 한국포장학회지
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• 제10권1호
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• pp.63-68
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• 2004

The regulations for migration amounts in USA, EU and Korea are investigated to compare the actual overall and specific migration date from plastic food packaging materials. Among the packaging materials regulated in above countries, printing ink solvents on packaging materials is used very widely and sometimes cause off-flavor in the food by migration of residual solvents. Even though migration of the residual solvents dose not generally cause safety problems in the contained food, it certainly can generate off-flavor and finally deteriorate quality of the finished product. Therefore regulation and development of analytical method for amount of residual ink solvents are very important issue in food industry. The headspace analytical method and tenax method for residual ink solvent on food packaging materials were evaluated from the accuracy, precise, swiftness and convenience of viewpoint. Headspace analytical method was selected and recommended for using in food industry field.

• Environmental Analysis Health and Toxicology
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• 제22권1호
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• pp.49-55
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• 2007

Three kind of ASE (Accelerated Solvent Extraction) and SPMDs (Semi-Permeable Membrane Devices) combined methods (ASE-SPMDs, ASE-accelerated SPMDs and SPMDs without extraction) and general Soxhlet-GPC were compared each other for the analysis of PCDD/FS in sediment. The average recovery rate of three types ASE and SPMDs combined methods (108.1%) were higher than that of the Soxhlet-GPC (79.5%) for three samples in each method using surrogate internal standards. The average coefficient of variation (10%, $2.1{\sim}25.2%$) for each congener of PCDD/Fs shows the reasonable results. Total PCDD/Fs concentrations after SPMDs without extraction were quite low, but those after ASE-SPMDs and ASE-accelerated SPMDs methods were close to the Soxhlet-GPC. Thus, the ASE-SPMDs and ASE-accelerated SPMDs methods are considered as the excellent pre-treatments method because they need less solvent and time without quality degradation.

• Journal of Microbiology and Biotechnology
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• 제5권5호
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• pp.302-304
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• 1995

As the previous HPLC method (Ogasawara et al., 1983) was described for the analysis of aclacinomycin A and some of its analogue compounds but not for aclacinomycin Y, we developed novel HPLC condition by optimizing solvent system. The newly developed solvent system allowed a complete separation of aclacinomycins Y and A, as opposed to the incomplete resolution of these two compounds in conventional method. The amounts of aclacinomycins Y and A could be accurately determined when the fermentation broth of Streptomyces lavendofoliae DKRS was analyzed by the newly developed method.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2382-2388
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• 2007

A series of dimethine cyanine dyes were synthesized in a fast, efficient and high yield by the condensation of quaternary salts with 1H-indole-3-carbaldehyde in the presence of piperidine under solvent-free microwave irradiation. The products were identified by 1H NMR, IR, UV-Vis spectra and elemental analysis. The absorption and fluorescence properties of these dyes were investigated both experimentally and theoretically. Calculations performed at a combination of time-dependent density functional theory (TD-DFT) and the polarizable continuum model (PCM) reproduced the π-π* type absorption bands of the dyes. Regression analysis was used for studying theoretical results of the absorption maxima in different solvents. Compared with experimental counterparts, estimated overall uncertainties in the absorption maxima were about ±2%.

• International Journal of Safety
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• 제9권1호
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• pp.43-46
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• 2010

In the recycle process of organic solvent, the atmospheric oxygen can cause autoxidation and product peroxide. The time-saving method to evaluate the hazards has been required. In this study, oxygen pressure monitoring experiment was proposed as a new method to evaluate autoxidative resistances of solvents. Some of organic solvents were pressurized by oxygen and kept under isothermal condition. At the same time, the pressure in the vessel tracked. Iodometrical titration, thermal analysis and spectroscopic analysis were performed to measure peroxide concentration, the heat of reaction and chemical bonding change. From the results that THF has larger oxygen consumption rate than CPME, it is considered that autoxidative resistance of THF is lower than that of CPME. This method enables to obtain results in shorter time than other methods. These experimental results were consistent with the previous research with longer test durations [1-2].

• 대한화학회지
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• 제62권4호
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• pp.265-268
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• 2018

The solvolyses of anthraquinone-2-carbonyl chloride (1) were studied kinetically in 27 pure and various mixed solvents. The analysis using the extended Grunwald-Winstein equation in the solvolyses of anthraquinone-2-carbonyl chloride (1) obtained the l value of $2.11{\pm}0.11$, the m value of $0.54{\pm}0.06$, and the correlation coefficient of 0.955. The solvolysis reaction of 1 might proceed via an associative $S_N2$ mechanism enhancing bond making than bond breaking in the transition state (TS). This interpretation is further supported by a relatively large solvent kinetic isotope effect (SKIE, 2.27).

• Bulletin of the Korean Chemical Society
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• 제21권11호
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• pp.1101-1105
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• 2000

A simultaneous determination method of BTEX (benzene, toluene, ethylbenzene, o,m.p-xylene) and TPH (kerosene, diesel, jet fuel and bunker C) in soil with gas chromatography/flame ionization detection (GC-FID) was described. The effects of extracti on method, extraction solvent, solvent volume and extraction time on the extraction performance were studied. A sonication method was simpler and more efficient than Soxhlet or shaking methods. Sonication with 10 mL of acetone/methylene chloride (1 : 1, v/v) for 10 min was found to be optimal extraction conditions for 20 g of soil. Peak shapes and quantification of BTEX and TPH were excellent, with linear calibration curves over a wide range of 1-500 mg/L for BTEX and 10-5000 mg/L for TPH. Good reproducibilities by sonication were obtained, with the RSD values below 10%. By using about 20 g of soil, detection limits were 0.8 mg/L for BTEX and 10 mg/L for TPH. The advantages of this procedure are the use of simple and common equipment, reduced volumes of organic solvents, rapid extraction periods of less than 20 min, and simultaneous analysis of volatile and semivolatile compounds.

• Mass Spectrometry Letters
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• 제14권3호
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• pp.79-90
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• 2023

Natural goods, especially therapeutic plants, are abundant in the World. Because they have the ability to provide all humanity with countless advantages as a source of medicines, medicinal plants are presently receiving more attention than ever. These plants' therapeutic efficacy is based on bioactive phytochemical components that have clear physiological effects on the human body. The drying process is crucial for the preparation of plant materials prior to extraction since freshly harvested plant materials include active enzymes that create active components, intermediates, and metabolic processes. Many of the phytoconstituents may be extracted using the semi-polar solvent methanol. The goal of the current work is to use the GC-MS gas chromatography- mass spectrometry technology to identify the phytochemicals and review their biological activity. In methanol leaf extract, 5 phytocompounds were found in Ricinus communis, 5 phytocompounds in Pongamia pinnata, 12 phytocompounds in Datura metal, 7 phytocompounds in Azadirachta indica, 11 phytocompounds in Acalypha indica.

• Natural Product Sciences
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• 제17권4호
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• pp.321-327
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• 2011

In this study, quantitative analysis was developed using HPLC/UVD for the quality evaluation of Scutellariae Radix. For quantitative analysis, six major bioactive compounds were assessed. The separation conditions employed for HPLC/UVD were optimized using Phenomenex $C_{18}$ column ($250{\times}4.6$ mm, 5 ${\mu}m$) with a gradient of solvent A (1% acetic acid of $H_2O$) and solvent B (acetonitrile : methanol : acetic acid = 70 : 30 : 1) as the mobile phase at a flow rate of 1.0 mL/min and a detection wavelength of 275 nm. These methods were fully validated with respect to linearity, accuracy, precision and recovery. The HPLC/UVD method was applied successfully to the quantification of six major compounds in the extract of Scutellariae Radix. The results indicate that the established HPLC/UVD method is suitable for the quantitative analysis and quality control of multicomponents in Scutellariae Radix.

• 한국안광학회지
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• 제9권2호
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• pp.257-267
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• 2004

본 연구에서는 전라남도 여수지역의 한 석유화학단지애서 적어도 6개월이상 근무한 작업자 1030명을 대상으로 Lanthony D-15-desaturated 검사법을 이용하여 유기용제노출과 후천적 색각이상간의 연관성을 조사하였다. 작업환경측정은 전 작업시간(8시간) 단시료를 각 작업자에게 부착하는 개인시료를 활용하여 각 개인별 평균, 최대, 누적 연평균 8hr TWA를 산출하였다. 연구결과 연령이 높을수록 색혼란지수(CCI)가 유의하게 높았다(P<0.005). 형태에서는 청황색각이상의 분포가 노출군과 비노출군간에 통계적으로 유의한 수준은 아니었지만, 후천적 색각이상에서 주로 나타나는 제3색형과 제4색형 그리고 복합형이 대부분 노출군에서 높은 분포(비노출군 6.16%, 7.55%, 13.71%, 노출군 5.9%, 7.86%, 14.99%)를 보였다. 마지막으로 색각이상과 관련된 변수들을 보정하였을 때, 후천적 색각이상이 좌안에서는 비노출군과 비교하여 볼 때 통계적 연관성은 없었으나 노출군의 Odds ratio가 증가함을 보였다. 또한 연령에 대하여는 좌 우안에서 모두 높은 통계적 연관성을 보였다(p<0.01). 따라서 이 상의 결과로 근로자가 유기용제 중독으로 인해 초기 신경계이상의 증상으로 후천적 색각이상이 존재할 수 있으므로 안보건 사업에서의 또 하나의 일환으로 근로자의 안보건상태에 대한 지속적인 관심과 관리가 필요하다.