• Analytical Science and Technology
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• v.23 no.6
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• pp.531-536
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• 2010

A quantitative analytical method has been established for the measurement of inosine 5'-monophosphate dehydrogenase (IMPDH) activity in human peripheral blood mononuclear cells (PBMCs) by ion-pair reversed-phase high performance liquid chromatography equipped with ultraviolet detection (HPLC/UV). IMPDH is a ${\beta}$-nicotinamide adenine dinucleotide hydrate (NAD+)-dependent dehydrogenase in which the enzyme converts inosine 5'-monophosphate (IMP) into xanthosine 5'-monophosphate (XMP). Its activity was measured by quantifying a HPLC chromatogram corresponding to XMP produced during the incubation of lysed PBMCs with IMP as a substrate and $NAD^+$ as a coenzyme. XMP produced was detected at a wavelength of 260 nm. The mobile phase was composed of a mixture of 37 mM potassium dihydrogen phosphate containing 7 mM tetra-n-butylammonium hydrogen sulfate adjusted to pH 5.5 and methanol (85:15, v/v) with a flow rate of 1 mL/min. The calibration curve was linear ($r^2$=0.999999) in the range of $0.2-50.0\;{\mu}M$ and the limit of quantification (LOQ) was $0.2\;{\mu}M$. The intra- and inter-day precisions were between 0.88-1.47% and 0.85-5.24%, respectively. The intra- and inter-day accuracies were between 98.74-99.99% and 99.95-101.65%, respectively. IMPDH activity in 11 Korean healthy volunteers ranged from 18.29 to 36.60 nmol/h/mg protein (mean = $27.70{\pm}6.28\;nmol/h/mg$ protein).

• Analytical Science and Technology
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• v.12 no.5
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• pp.408-414
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• 1999

A selective and sensitive method for the derivatization of total homocysteine (Hcy) and the related compounds in plasma by gas chromatograph (GC)-electron capture detector (ECD) has been developed. To determine total homocysteine, cysteine (Cys), and methionine (Met) in human plasma using GC-ECD, analytes were reduced and converted into their N(O,S)-ethylearbonyl pentafluoropropyl (PFP) ester by derivatization with ethyl chloroformate and pentafluoropropyl alcohol (PFP-OH) in plasma. The best derivatizing agent N(O,S)-ethyl carbonyl PFP ester, was chosen by comparing the sensitivity of derivatized analysis in GC-ECD. The derivatized analytes in plasma were extracted by chloroform, and subsequently back-extracted with hexane and analyzed by GC-ECD. The calibration carves ($R^2$ > 0.990) were linear over the range $5-50{\mu}mol/L$ of Hcy and Met, $40-400{\mu}mol/L$ of Cys spiked in plasma. The detection limit observed by the established method was below $0.5{\mu}mol/L$. This method is highly sensitive and specific in the analysis of Hcy, Cys, and Met. Therefore, we suggest that this method is appropriate in the analysis of trace concentration of Hcy, Cys, and Met in biological fluids.

• Analytical Science and Technology
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• v.16 no.6
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• pp.483-487
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• 2003

Amitrole is well-known as a non-selective herbicide and it is able to cause contamination of driking water as well as pollution of ground water and surface water. However, it is difficult to extract from water because it has a high solubility for water whereas a low solubility for general organic solvents. This method is described for the determination of amitrole in water samples by GC/MS. After evaporation of 10 mL water sample by a vacuum evaporator, amitrole was derivatized with isobutyl chloroformate (iso-BCF) on room temperature for 15~20 min. As a result, the sensitivity for GCfMS was improved as N-isobutoxycarbonyl amitrole derivative was formed. The linearity of the calibration curve showed good as 0.997. The recoveries were obtained more than 94.9% and relative standard deviations were less than 2.8% at $1.0{\mu}g/L$, $10.0{\mu}g/L$ and $100.0{\mu}g/L$. The limit of detection showed $0.1{\mu}g/L$ with a signal-to-noise ratio (S/N) of 3.

• Analytical Science and Technology
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• v.13 no.4
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• pp.453-465
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• 2000

Polycyclic aromatic hydrocarbons (PAHs) were produced by thermoreaction (incompletely combustion) of organic compounds such as fuel, gasoline, diesel etc, and were known the strong carcinogenic compounds. In our country, a study for health risk assessment of PAHs in air were needed according to rapidly increasing of motor vehicle and progressing to industrial country. In this study, concentrations of PAHs in 263 air samples of fourteen sites-Seoul, Pusan, etc-according to four times sampling for one year are measured by GC/MSD for basic research for health risk assessment. As the result, 14 PAHs are detected in all samples and annual average concentration of total PAHs was $28.72ng/m^3$ and highest average concentration of total PARs was $47.76ng/m^3$ in winter season. The concentrations of total PAHs are proportioned to amount of extracted organic material (EOM). The average concentration of total PAHs in EOM was 0.28%.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.167.2-167
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• 1998

No Abstract, See Full Text

• Proceedings of the Korean Nutrition Society Conference
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• 2003.05a
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• pp.124.2-124.2
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• 2003

• Analytical Science and Technology
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• v.18 no.3
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• pp.173-187
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• 2005

• Toxicological Research
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• v.16 no.2
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• pp.117-124
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• 2000

The objective of this experiment is to investigate neurobehavioral and developmental effects of fumonisin B1 (FB1) after prenatal FB1 administration in rats. FB1 (0.8 or 1.6 mg/kg) was orally exposed to pregnant rats during gestational days 13 to 20, whereas the vehicle alone was administered to control group. Maternal and offspring body weights, physical landmarks of incisor eruption, eye opening, testes descending and vaginal opening, open field activity, running wheel activity, and complex maze performance were included as endpoints for developmental and neurobehavioral measurement. Maternal body weights were not signfficantly altered after FB1 exposure. Percentage of maternal weight gain difference between control and 1.6 mg/kg FBI groups was about 4%. Pre- and post-weanling weight of offsprings after prenatal exposure to FB1 was not signfficantly changed, suggesting that FB1 at 0.8 or 1.6 kg/kg doses may not cross the placenta. Significant gender difference in running wheel activity on postnatal days 57 to 63 and complex maze performance on postnatal days 75 to 78 was observed.

• Journal of Applied Biological Chemistry
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• v.44 no.4
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• pp.180-184
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• 2001

To investigate the hepatic metabolism of myristicin isolated rat livers were perfused under single-pass conditions with perfusate containing myristicin. In outflow perfusate and bile, 5-allyl-1-methoxy-2,3-dihydroxybenzene (M1), M1-sulfate, and M1-glucuronide conjugates were identified as the metabolites of myristicin. HPLC method with UV detection was applied to investigate the hepatic disposition of the compounds. The concentration of myristicin, M1, and M1-conjugates in the outflow perfusate reached steady-state levels within 20 min after commencing the perfusion of $4.5{\mu}M$ myristicin. At steady-state, the mean (${\pm}S.D.$) extraction ratio of myristicin was $0.49({\pm}0.16)$ and clearance was $13.7({\pm}4.5)ml/min$. M1 accounted for $44.0{\pm}5.3%$ of eliminated myristicin and was recovered as unchanged M1, M1-sulfate, and M1-glucuronide in the bile and outflow perfusate.

• Clinical and Experimental Reproductive Medicine
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• v.30 no.1
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• pp.23-29
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• 2003

목 적: 본 연구의 목적은 내인성 성호르몬이 자궁근종의 성장에 미치는 영향을 알아보고자 연구를 시행하였다. 연구대상 및 방법: 폐경전 자궁근종 환자 27명과 같은 연령대의 정상여성 25명을 대상으로 하였다. 모든 대상군의 여성에서 24시간 소변을 모아서 소변내 estrogen, androgen의 대사체들을 GC-MS를 이용하여 측정하였으며 두 군에서의 차이를 비교분석 하였다. 결 과: 소변내 $17{\beta}$-estradiol, 5-androstene-$3{\beta}$, $16{\beta}$, $17{\beta}$-triol, 11-keto-ethiocholanolone, $11{\beta}$-hydroxy-androsterone, THS, THA, THE, a-cortolone, a-cortol 및 $\beta$-cortol가 환자군에서 의의있게 증가하였으며 $17{\beta}$estradiol/estrone 및 $11{\beta}$-hydroxy-ethiocholanolone/$11{\beta}$-hydroxy-androsterone도 환자군에서 의의있게 증가하였다. 결 론: 자궁근종의 성장은 요중 estrogen과 androgen의 농도와 밀접한 관련이 있으며 이는 환자의 스테로이드 호르몬 대사 감소에 기인한 것으로 사료된다.