• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2293-2298
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• 2007

In this study, a dithizone extraction technique involving purge & trap GC-MS was developed for the determination of methylmercury in biological samples, especially blood and fish. After alkaline digestion, methylmercury in biological samples was extracted into dithizone and back-extracted into aqueous sulfide solution. The extracted methylmercury was converted to the volatile ethyl derivative, purged and trapped onto a solid-phase collection medium, and then introduced into the GC-MS system. The determined MDLs of the established method were 0.9 ng·g?1 for biological samples and its accuracy and precision were found to be 93% and 3.8%, respectively. The method was validated by analysis of CRMs such as SRM 966, BCR 463 and IAEA 407 and all analytical results were within certified ranges with average RSDs of less than 6%. The analytical results of field-sampled fish also showed that the method can be successfully used as an alternative for commonly used distillation method followed by GC-CVAFS detection.

• 보건의료산업학회지
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• 제8권2호
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• pp.139-148
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• 2014

The purpose of this study was to analyze the factors affecting the unmet dental needs of Koreans. In relation to the subjects and methodology for this study, the data from the 5th national health nutrition survey which had been conducted between 2010 and 2012 were analyzed by using the PASW statistics 18.0 (SPSS Inc., Chicago, IL, USA), a statistical program, through the frequency analysis of complex samples, cross analysis of complex samples, and logistics regression analysis of complex samples. The results of analysis showed that the rate of unmet dental needs stood at 35.3% of all subjects. Moreover, to determine the factors related to the unmet dental needs, the logistics regression analysis of complex samples was conducted. The results of analysis showed that the demographic and socio-economic factors and oral health condition factors had relationship with unmet dental needs. It is necessary to consider all the objective dental treatments that reflect specific dental diagnosis from a comprehensive standpoint.

• 한국엔터테인먼트산업학회논문지
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• 제13권8호
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• pp.357-365
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• 2019

본 연구의 목적은 대사증후군을 가진 사람의 성별, 연령에 따른 건강관련 삶의 질(EQ-5D)의 차이를 확인하는 것이다. 국민건강영양조사(KNHANES VI-2)에 응답한 5,021명의 자료를 이용하여 대사증후군 판정을 하였으며, IBM SPSS STATISTICS 25.0의 복합표본분석을 적용한 빈도분석, 교차분석과 Complex Samples GLM과 Complex Samples t-test를 사용하였다. 연구결과 EQ-5D 지수에 있어서 남성이 여성보다 다소 높았다(p<.001). 연령별로는 청장년(19~39세), 중년(40~65세), 노년(65세 이상)의 순서로 높게 확인되었다(p<.001). 대사증후군 여부로는 대사증후군에 속하지 않는 경우가 대사증후군을 가진 경우보다 추정치가 높게 나타났으나 통계적으로 유의하지는 않았다. 대사증후군 여부로는 대사증후군이 있는 경우에 그렇지 않은 경우보다 건강관련 삶의 질이 추정치에서 낮음으로 나타났으나 통계적으로 유의하지 않았다(p>.05). 한편, 전체 모집단(population)에서 성인을 대상으로 복합표본을 적용한 독립표본 t 검정(Complex Samples Independent t-test)을 통해 성별 간 대사증후군 유병여부에 따른 EQ-5D는 여성의 경우 대사증후군에 속하지 않은 경우가 대사증후군에 속하는 경우 보다 높은 지수가 확인되었으며 통계적으로 유의한 차이가 확인되었다(p<.01).

• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3151-3155
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• 2010

This study was performed to develop analytical methods to better understand the properties and reactivity of petroleum, which is a highly complex organic mixture, using high-resolution mass spectrometry and statistical analysis. Ten crude oil samples were analyzed using negative-mode electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). Clustering methods, including principle component analysis (PCA), hierarchical clustering analysis (HCA), and k-means clustering, were used to comparatively interpret the spectra. All the methods were consistent and showed that oxygen and sulfur-containing heteroatom species played important roles in clustering samples or peaks. The oxygen-containing samples had higher acidity than the other samples, and the clustering results were linked to properties of the crude oils. This study demonstrated that clustering methods provide a simple and effective way to interpret complex petroleomic data.

• Journal of Industrial and Engineering Chemistry
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• 제67권
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• pp.461-468
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• 2018

A highly sensitive, selective and rapid method for the determination of lead based on the reaction of lead (II) with 5-(4'-chlorophenylazo)-6-hydroxypyrimidine-2,4-dione (CPAHPD) and the solid phase extraction of the Pb(II)-CPAHPD complex with Amberlite XAD-2000 was developed, in the presence of pH 5.6 buffer solution and Triton X-114 medium. CPAHPD reacts with lead to form a violet complex with a molar ratio of 2:1 (CPAHPD to lead). This complex was enriched by the solid phase extraction with Amberlite XAD-2000. An enrichment factor of 500 was obtained by elution of the complex from the resin with a minimal amount of isopentyl alcohol(0.2 mL). In isopentyl alcohol medium,the molar absorptivity of the complex is $1.13{\times}10^6L\;mol^{-1}cm^{-1}$ at 647 nm. Beer's law is obeyed in the range of $5.0-160ng\;mL^{-1}$ in the measured solution. The relative standard deviation for 10 replicate samples of $50ng\;mL^{-1}$ level is 1.26%. The detection and quantification limits reaches 1.5 and $4.7ng\;mL^{-1}$ in the original samples. The presented procedure was successfully applied for determination of lead content in real samples such as vegetables, waters, biological and soil samples with satisfactory results.

• Bulletin of the Korean Chemical Society
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• 제27권4호
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• pp.563-567
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• 2006

The application of a synergistic solvent extraction by the formation of ternary complex with pyrocatechol violet (PV) and benzalkonium chloride (BC) was studied for determination of trace Zn(II) in water samples. The pH of sample solution and the amount of PV and BC added were optimized for the formation of the stable complex, a proper solvent was selected for the effective extraction, and the concentration of nitric acid was fixed for the back extraction of the complex from the solvent. After the ionic strength of 100 mL sample solution was adjusted to 0.1 M by adding NaCl and the pH was fixed at 9 with a carbonate buffer, 1.0 mL of 2% PV solution was added to form Zn(II)-PV complex then the Zn(II)-PV/BC ternary complex was made by adding 1.0 mL of 10% BC solution. The ternary complex was extracted into 10 mL of MIBK. And the ternary complex was back-extracted with 10 mL of 1.0 mol/L nitric acid to determine Zn(II) by a flame atomic absorption spectrophotometer (flame-AAS). The interference of concomitant ions on the extraction of Zn(II) was investigated. This procedure was applied to the analysis of three real samples such as Dalbang-dam water, laboratory tap water and Jungnajin seawater. The recoveries of Zn(II) in spiked samples were 86.58-104.1%.

• 융합정보논문지
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• 제10권10호
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• pp.268-272
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• 2020

본 연구는 경제활동자의 구강 건강과 자살 생각과의 관련성을 알아보기 위해 우리나라 국민건강영양조사의 자료를 바탕으로 연구하여 경제활동자의 자살 예방과 구강건강 증진을 위한 기초자료로 활용하고자 한다. 자료분석은 복합표본 빈도분석, 복합표본교차분석, 복합표본 로지스틱 회귀분석을 통계프로그램 IBM SPSS Statistics 20.0으로 사용하여 분석하였다. 연구결과, 구강 건강과 자살 생각과의 관련성은 저작 불편 있는 경우 2.49배로 유의하게 높게 나타났다. 따라서 경제활동자들의 자살생각을 감소시킬수 있는 요인으로 구강건강관리가 필요함을 알 수 있다.

• 한국환경과학회지
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• 제33권2호
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• pp.161-168
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• 2024

This study was conducted to identify the pollutants generated by the fuel complex and to determine the health effects of the surrounding residents. In addition, based on the results of epidemiological surveys and health impact surveys of local residents, we analyze the distribution of patient groups and exposure characteristics according to the distance from the fuel complex boundary. Samples were collected from the briquette plant within the fuel complex and analyzed by SEM-EDXA, X-ray Fluorescence Spectrometer, and ICP. In addition, the distribution of patients and exposure characteristics were analyzed according to the distance from the fuel complex and yard boundaries. Analysis of briquette samples from the fuel complex showed that the average particle size was 10-30 ㎛, the shape was irregular, and SiO₂ accounted for more than 50%. It is believed that silica, which causes pneumoconiosis, may have been scattered into the air. In particular, there was a large distribution of 5 ㎛ particles that affect respiratory diseases. According to the analysis of the residential addresses and distribution of pneumoconiosis cases, many pneumoconiosis cases were located in the area between 200 and 500 meters from the boundary of the fuel complex. In addition, 28 pneumoconiosis cases were identified as a result of the epidemiological survey and health impact survey at the fuel complex. In detail, there were 8 cases of occupational pneumoconiosis, 6 cases of environmental pneumoconiosis, and 14 cases of occupational and environmental pneumoconiosis. The confirmed pneumoconiosis cases were located between 0.3 and 1.1 kilometers from the fuel complex. It was found that environmental pollutants generated by the fuel complex adversely affect the health of local residents. In particular, there are many cases of pneumoconiosis in the area between 200 and 500 meters from the boundary of the fuel complex, and this distance is considered to be the direct and indirect impact zone of the briquette plant.

• 분석과학
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• 제31권4호
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• pp.171-178
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• 2018

Recently, for successful lactation, many breastfeeding mothers seek various products, including herbal medicine, dietary supplements, and prescribed medicines, to improve milk production. As demand for galactogogues grows, it is highly possible that pharmaceutical galactogogues may be adulterated with illegal products to maximize their efficacy. For continuous control and supervision of illegal products, we developed and validated a simple and sensitive LC-MS/MS method capable of simultaneously determining five galactogogues. Chromatographic separation was conducted using an Agilent Poroshell $120SB-C_{18}$ column with a mobile phase consisting of 20 mM ammonium formate (pH 5.4) and 100 % acetonitrile. The total run time was 13 min per analyte. The proposed method was performed according to the guidelines of the International Conference of Harmonization and it produced reliable results. This method showed high sensitivity and specificity, with a limit of detection (LOD) and limit of quantitation (LOQ) of 0.01-0.82 ng/mL and 0.02-2.45 ng/mL, respectively, for the solid- and liquid-type samples. Specificity was evaluated by analyzing matrix-blank samples spiked with the target compounds at LOQ levels, which provided a good separation of all peaks without interference. Additionally, the repeatability and intermediate precision were typically <15 %, whereas the recovery was 80-120 % of the values obtained using blank samples. Thus, we concluded that this method could be used for the identification and quantification of galactogogues in food or herbal products.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2003년도 International Symposium on Clean Environment
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• pp.113-118
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• 2003

An investigation has been carried out on collision-induced dissociation (CID) in the development of an analytical protocol for the determination of polycyclic aromatic hydrocarbons (PARs) by ion trap tandem mass spectrometry. Two different considerations were used to choose the optimal CID conditions for complex matrix environmental samples, namely, to determine the highest signal-to-noise (SIN) ratio and the other to eliminate the background interferences originated from complex matrix samples. The PAR content of agricultural soil was measured to estimate overall distribution of PAR in throughout the country, we collected and analyzed 226 soil samples from paddy and upland soil. The average content of total PAR in all samples was 236 ${\mu}g$ $kg^{-1}$, and the range was from 23.3 to 2, 834 ${\mu}g$ $kg^{-1}$. The overall distribution of PAR was found to be closely related to the pollution sources, the size of city and the type of industry.