• BMB Reports
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• v.29 no.2
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• pp.105-110
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• 1996

Polyclonal antiserum R101 against aflatoxin $B_1$ ($AFB_1$) was raised in New Zealand white rabbits after injection of bovine serum albumin-$AFB_1$ conjugate. Competitive ELISA (enzyme linked immuno-sorbent assay) demonstrated that antiserum R101 has the highest binding for $AFB_1$ (50% inhibition at 170 fmol) and aflatoxicol II (50% inhibition at 112 fmol). It also reacts with other aflatoxins such as $AFB_2$, $AFG_1$, $AFG_2$, and aflatoxin metabolites ($AFM_1$, $AFM_2$, $AFP_1$, and $AFQ_1$), but it does not cross-react with $AFG_2a$. Using this antiserum, aflatoxins were quantitated in 100 urine samples of undergraduate students at the College of Pharmacy, Sung Kyun Kwan University, Republic of Korea. By ELISA, $AFB_1$ and its metabolites were detected in human urine samples (N=100, male=89, female=11, ages=20~31 yrs) with a range of 1.4~200.6 ng/kg/day (mean$\pm$SD=$18.11{\pm}33.01\;ng\;AFB_1/kg/day$ in males, $3.82{\pm}2.65\;ng/kg/day$ in females). Assuming that urinary excretion is about 7.6% of $AFB_1$ intake (Groopman et al., 1992), we estimated that Koreans were daily exposed to a total dietary $AFB_1$ of $240.20{\pm}438.67\;ng/kg/day$ in males and $50.35{\pm}29.88\;ng/kg/day$ in females, respectively. When the human monitoring data was applied to a linear regression model of Y=21.67X-10.04 {Y=liver cancer incidence per 100,000, X=Log $AFB_1$ intake (ng/kg/day), r=0.99} developed from previously reported epidemiological data, calculated liver cancer incidences attributed to $AFB_1$ exposure were 41.56/100,000 in males and 26.84/100,000 in females. The incidences were similarly correlated with liver cancer mortality rates of 43.43/100,000 in males and 11.23/100,000 in females in Korea. These results suggest that aflatoxin exposure may be an important risk factor for the high incidence of liver cancer in Korea.

• Journal of Environmental Health Sciences
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• v.39 no.5
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• pp.408-417
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• 2013

Objectives: Phthalates are used as plasticizers in polyvinyl chloride (PVC) plastics. As phthalate plasticizers are not chemically bound to the PVC, they can leach, migrate or evaporate into indoor air and atmosphere, foodstuffs, other materials, etc. Therefore, humans are exposed through ingestion, inhalation, and dermal exposure over their entire lifetime, including during intrauterine development. In particular, university students have a great number of opportunities to contact products including phthalates during campus life (food packaging, body care products, cosmetic, lotions, aftershave, perfume etc.). The purpose of this study was to examine levels of phthalate exposure as undergraduate students begin to use pharmaceuticals and personal care products including phthalates. Methods: Phthalate metabolites, mono-ethyl phthalate (MEP), mono-n-butyl phthalate (MnBP), mono-isobutyl phthalate (MiBP), mono-2- ethylhexyl phthalate (MEHP), {(mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP}, and mono-(2-ethlyl-5-oxohexyl) phthalate (MEOHP} were examined. 80 urine samples collected from university students were analyzed using LC/MS/MS(API 4000, Applied Bioscience) with on-line enrichment and columnswitching techniques. This study was carried out at Y university located in Gyonggi Province from 2008 to 2011. Results: The detection limit of phthalate metabolites were 0.03 ng/mL for MEP, 0.11 ng/mL for MnBP, 0.08 ng/mL for MiBP, 0.93 ng/mL for MEHP, 0.19 ng/mL for MEOHP and 0.16ng/mL for MEHHP. MnBP showed the highest urinary levels (median: 31.6 ug/L, 24.8 ug/g creatinine (cr)). Concentrations were also high for MEHHP (median: 24.1 ug/L, 19.0 ug/g cr), followed by MEOHP (median: 22.8 ug/L, 17.9 ug/g cr). In individual cases, the maximum level reached up to 348 ug/L, and 291 ug/g cr, respectively. The urinary and creatinine adjusted levels of MEP were lower than those for DBP and DEHP metabolites, but were higher in 95th percentiles. As a result, the mean daily DEP intake value was 2.3 ${\mu}g/kg$ bw/day, 3.5 ${\mu}g/kg$ bw/day for DEHP and 4.9 ${\mu}g/kg$ bw/day for DBP. Conclusion: These students' phthalate exposure levels were below the international safe level set by the EU, but higher than the 2012 KFDA survey of the age group from 3 to 18.

• Journal of the Korean Chemical Society
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• v.64 no.4
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• pp.203-209
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• 2020

Selenium species in hair and nails were extracted, separated and analyzed with HPLC-ICP/MS. The result showed that Se species was mostly SeCys and the information related to the change of selenium concentration in a body could be obtained. The Se fortification study was performed for 5 participants during 12 months. The average of Se concentration was 858.6 ± 201.2 ng g^-1, which did not change much during the research period nor the difference between the individuals was striking. In the case of hair, the average concentration was 205.3 ng g^-1 which was lower than nails. Se supplement of 22 ㎍ day^-1 was taken for 3 months by the volunteers and the difference between before and after (3 months period for each) the taking of supplement was not striking. However, when the dose was increased to 300 ㎍ day^-1 for 2 months, the concentration was increased noticeably to 1,230 ng g^-1. It can be thought that the analysis of finger nail for Se can provide valuable information for the long period (several months) of exposure or intake of Se for a human body.

• Analytical Science and Technology
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• v.17 no.3
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• pp.263-270
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• 2004

A method is described for the analysis of short-chain alkylphenol ethoxylates (APEOs), 4-octylphenol-di-ethoxylate (OP2EO) and 4-nonylphenol-di-ethoxylate (NP2EO), in drinking water or wastewater using reversed phase high-performance liquid chromatography with electrospray ionization mass spectrometry. The solvent system was water and methanol containing $10{\mu}M$ trifluoroacetic acid as an ionization solvent. We acidified 1 L of water samples to less than pH 2 with concentrated $H_2SO_4$ and loaded onto Sep-Pak $C_{18}$, and eluted with acetone. The calibration of OP2EO and NP2EO was performed for the concentration range from 20 to 500 ng/L and the correlation coefficients were 0.999 and 0.990, respectively. The limits of detection were 20 ng/L (OP2EO) and 50 ng/L (NP2EO) at a signal-to-noise ratio of 3. Accuracy and precision of this analytical method were 85.8 ~ 122.1% and 8.2 ~ 18.8%, respectively. The proposed method allowed a sensitive and rapid detection of OP2EO and NP2EO and it could be applied for monitoring of APEOs from environmental samples.

• Herbal Formula Science
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• v.19 no.1
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• pp.35-49
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• 2011

Objectives : This study aims to reveal the characteristics of formulas in "Xi$\v{a}$o' Er Y$\`{a}$o Zh$\`{e}$ng Zh$\'{\i}$ Ju$\'{\e}$. Methods : For that objectives, We analyzes formulas in "Xi$\v{a}$o' Er Y$\`{a}$o Zh$\`{e}$ng Zh$\'{\i}$ Ju$\'{\e}$. In the text, 132 formulas were described. To comprehend the formulas, we classified them as several bases. Results : After those analyses, we bring to a conclusion as follows. 1. 30 formulas are described that treated convulsive diseases (j$\={i}$ngf$\={e}$ng, 惊風). Next, g$\={a}$n(疳), parasite infection, diarrhea/dysentery, dermatosis and etc were in the order. 2. Classified by the formulation, Yu$\'{\a}$nj$\`{i}$(圓劑) was the best(70 kinds of formulas, 53%). S$\v{a}$nj$\`{i}$(散劑) was a form of 41 formulas(31%). T$\={a}$ngj$\`{i}$(湯劑) and g$\={a}$oj$\`{i}$(膏劑) were a form of 5 formulas each. 10 formulas were assumed the form of w$\`{a}$iy$\`{o}$ngj$\`{i}$(外用劑). 3. We researched in-depth analysis of Yu$\'{\a}$nj$\`{i}$. As a results, dosage, additive(輔料) and the time to take of Yu$\'{\a}$nj$\`{i}$ were decomposed. Also, the formulas that treated convulsive diseases were analyzed by the herbs classification. Conclusions : Though the formulas that treated convulsive diseases were hard to application at local clinic, overall nosology of pediatrics was reflected comparatively. "Xi$\v{a}$o' Er Y$\`{a}$o Zh$\`{e}$ng Zh$\'{\i}$ Ju$\'{\e}$ was expected to play a role for reconsideration of formulas' formulation.

• Journal of Korea Entertainment Industry Association
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• v.13 no.5
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• pp.139-143
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• 2019

The aim of this study was to assess the association of vitamin D and urine microalbumin/creatinine (uACR) and obesity. The study subjects were Korean adults 20 years or older (n = 4,948) who participated in the Korea National Health and Nutrition Examination Survey 2012. Analysis of covariance test adjusted for covariates were performed for uACR levels in relation to vitamin D status [vitamin D deficient, 25(OH)D < 10 ng/dL; vitamin D insufficient, 25(OH)D ≥ 10, < 20 ng/dL; vitamin D sufficient, 25(OH)D ≥ 20 ng/dL]. The key study results were as follows: First, in the populations without obesity (BMI < 25 kg/m²), uACR levels were decreased with the increasing of vitamin D status (p < 0.001) after adjusting for relevant variables. Second, in the populations with obesity (BMI ≥ 25 kg/m²), the association between uACR levels and vitamin D status was not significant (p = 0.659). In conclusion, urine microalbumin/creatinine levels were inversely associated with vitamin D status in Korean adults without obesity, but not in Korean adults with obesity.

• Clinical and Experimental Reproductive Medicine
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• v.40 no.3
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• pp.135-140
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• 2013

Objective: To evaluate correlations between serum anti-M${\ddot{u}}$llerian hormone (AMH) levels, phenotypes of polycystic ovary syndrome (PCOS), obesity, and metabolic parameters in patients with PCOS. Methods: A total of 175 patients with PCOS were diagnosed according to the Rotterdam Consensus were included. Exclusion criteria were age over 40, FSH>25 mIU/mL, and 17a-OHP>1.5 ng/mL. The Phenotypes of PCOS were divided into a severe form (oligo-anovulation, ANOV/hyperandrogenism/polycystic ovary morphology [PCOM]; n=59) and a mild form without HA (ANOV/PCOM, n=105). The serum AMH levels were classified into 3 groups (<5 vs. 5-10 vs. >10 ng/mL). Obesity was defined as body mass index (BMI) ${\geq}25kg/m^2$ (n=34). Results: The mean age was $25.9{\pm}5.7$ year and mean AMH level was $10.1{\pm}5.4$ ng/mL. The BMI ($kg/m^2$) was higher in group 1 ($24.2{\pm}6.3$) than in group 2 ($21.9{\pm}4.3$, p=0.046) or group 3 ($21.6{\pm}3.3$, p=0.019). There was no difference among the three groups in age, menstrual interval, antral follicle counts, androgens, or other metabolic parameters. The obesity group showed significantly lower AMH ($7.7{\pm}3.9$ ng/mL vs. $10.7{\pm}5.6$ ng/mL), p=0.004) and low-density lipoprotein levels ($93.1{\pm}21.2$ mg/dL vs. $107.5{\pm}39.3$ mg/dL, p=0.031), and showed higher total T ($0.74{\pm}0.59$ L vs. $0.47{\pm}0.36$ ng/mL, p=0.001), free T ($2.01{\pm}1.9$ vs. $1.04{\pm}0.8$ pg/mL, p=0.0001), and free androgen index ($6.2{\pm}7.9$ vs. $3.5{\pm}3.0$, p=0.003). After controlling for age factors and BMI, the serum AMH levles did not show any significant correlations with other hormonal or metabolic parmeters. Conclusion: For PCOS patients under the age 40, serum AMH is not negatively correlated with age. High serum AMH levels can not predict the phenotype of PCOS and metabolic disturbances in PCOS patients in the non-obese group. Further study might be needed to define the relation more clearly.

• Journal of Conservation Science
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• v.3 no.1 s.3
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• pp.23-30
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• 1994

This thesis researched for the conservation of a suit of armor that General Jung, Choong Sin had been worn in the 17th century, and of military uniform that was in perfect condition even though it had been underground for over 300years since 1676. As the armor was made with silk and cotton, it was treated by the dry cleaning method and the mild charge system. In the dry cleaning method, the used solvents were n-hexane and n-decane. And the percentage of the dry soap was 2 in the mild charge system. As the military uniform was made with only silk, it was treated by the dry cleaning method through the solvent of n-hexane and n-decane. Armor was repaired by scoured hemp partially, but military uniform became too deteriorated seriously to repair.

• Journal of the Korean Chemical Society
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• v.63 no.6
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• pp.415-419
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• 2019

Fipronil is an insecticide that belongs to the N-phenylpytazole and has been used mainly for an insect pest control. However, it is known that acute poisoning of the human body causes various symptoms such as dizziness, muscle weakness, dyspnea, skin irritation, and increased heart rate. Lately, eggs containing fipronil have been distributed and toxic problems are spreading around the world. In this study, we tried to develop analytical methods to evaluate the exposure of fipronil and fipronil sulfone in animal serum samples. The differences according to mobile phase and the results of liquid - liquid extraction and solid phase extraction pretreatment method were compared. Distilled water (A) and acetonitrile (B) were selected for the mobile phase, and the pretreatment method was determined by solid phase extraction. As a result of the method validation, the intra-day / inter-day accuracies were 82.2~114.1% and the precisions were less than 20%. The detection limit was 0.027 ng/ml for fipronil and 0.087 ng/ml for fipronil sulfone. The linearity obtained was satisfying, with a coefficient of determination (r²) higher than 0.99. The concentrations in some animal sera were determined using the methods of analysis for fipronil and fipronil sulfone in animal sera developed in this study. Using the method developed in this study, it could be used as an analytical method for human bio-monitoring of fipronil and fipronil sulfone as well as animal serum.

• Analytical Science and Technology
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• v.24 no.6
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• pp.421-428
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• 2011

In this study, headspace disk type monolithic material sorptive extraction (HS-MMSE) was developed, validated and applied to the analysis of volatile aroma compounds from vanilla perfume by gas chromatography -mass spectrometry (GC/MS). HS-MMSE uses monolithic material (MonoTrap) based on silica bonded with octadecyl silane (ODS) and activated carbon as a sorbent. Aroma compounds was adsorbed onto the MonoTrap in headspace and extracted by only 100 ${\mu}L$ of solvent. Total 12 volatile compounds from vanilla perfume were successfully analyzed using HS-MMSE. The influence of extractive parameters was investigated and optimized, using benzyl acetate, linalyl acetate, vanillin, ethyl vanillin as target compounds. Under the optimum condition, the limit of detection (S/N = 3) and the limit of quantification (S/N = 10) of proposed method for the target compounds were obtained within the range of 8.35~13.76 ng and 27.82~45.88 ng, respectively. The method showed good linearity with correlation coefficient more than 0.9888, satisfactory recovery and reproducibility. These results showed that HS-MMSE using disk type MonoTrap is a new promising technique for the analysis of volatile aroma compounds from vanilla perfume.