• Archives of Pharmacal Research
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• 제23권2호
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• pp.178-181
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• 2000

In order to study the simultaneous determination of (+)- and (-)-cetirizine in human urine we have developed a chiral separation method by HPLC. A chiral stationary phase of $\alpha$$_1$-acidglycoprotein, the AGP-CSP was used to separate the enantiomers. The pH of the phosphate buffer, as well as the content of the organic modifier in the mobile phase, markedly affected the chromatographic separation of (+)- and (-)-cetirizine. A mobile phase of 10 m㏖/1 phosphate buffer (pH 7.0)-acetonitrile (95 : 5, v/v) was used for the urine assays. Ultraviolet absorption was monitored at 230nm and roxatidine was employed as the internal standard for quantification. (+)-Cetirizine, (-)-cetirizine and the internal standard were eluted at retention times of 12, 16, and 32 mins, respectively. The detection limit for cetirizine enantiomers was 400 ng/$m\ell$ of urine. A pharmacokinetic study was conducted with the help of 5 healthy female volunteers who were administered with a single oral dose of racemic cetirizine (20 mg). The peak area ratios provided by the cetirizine enantiomers were linear(r>0.997) over a concentration range of 2.5-200 ${\mu}g/ml$. The peak of the excreted cetirizine enantiomers appeared in the urine sample during the period of 1-2 hrs following the administration of the oral dose. The excreted level of (+)-cetirizine was slightly higher than (-)-cetirizine but the difference was not statistically significant. However, this method appears to have applications for enantioselective pharmacokinetic studies of racemic drugs.

• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.105-110
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• 2012

A europium (III)-sensitized, spectrofluorimetric (FL) method is presented for the determination of sparfloxacin (SPAR) using an anionic surfactant, sodium dodecyl benzene sulphonate (SDBS). The method is based on the strong fluorescence (FL) enhancement of SPAR after the addition of $Eu^{3+}$ ions as fluorescence probes. The experimental results indicated that the FL intensity of the SPAR-$Eu^{3+}$ system was enhanced markedly by SDBS. The maximum FL emission signal was obtained at about 615 nm when excited at 372 nm. The experimental conditions that affected the FL intensity of the SPAR-$Eu^{3+}$-SDBS system were optimized systematically. The enhanced FL intensity of the system exhibited a good linear relationship with the SPAR concentration over the range of $1.5{\times}10^{-9}-1.2{\times}10^{-7}mol\;L^{-1}$ with a correlation coefficient (r) of 0.9987. The limit of detection ($3{\delta}$) was $4.15{\times}10^{-10}mol\;L^{-1}$ with a relative standard deviation (RSD) of 1.65%. This method was successfully applied for the determination of SPAR in pharmaceuticals, and human serum and urine samples with higher sensitivity, wide dynamic range and better stability. The possible interaction mechanism of the system is also discussed in detail by ultraviolet absorption spectra and FL spectra.

• 한국약용작물학회지
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• 제24권3호
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• pp.237-245
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• 2016

Background: Cyanazine is used as a pre-emergent herbicide once during the growing season to control weeds of many upland crops worldwide. This study aimed to establish a method to determined cyanazine residue levels in major medicinal crops by using high performance liquid chromatography-UV detection/mass spectometry (HPLC-UVD/MS). Methods and Results: Cyanazine residue was extracted with acetone from the raw products of four representative medicinal plants - Scutellaria baicalensis, Paeonia lactiflora, Platycodon grandiflorum and Angelica gigas. The extract was diluted with a large volume of saline water and directly partitioned into dichloromethane to remove polar co-extractives in the aqueous phase. It was then purifined using optimized Florisil column chromatography. HPLC analysis conducted using an octadecylsilyl column allowed the successful separation of cyanazine from co-extractives of the samples, and the amount was sensitively quantified by ultraviolet absorption at 225 nm with no interference. The accuracy and precision of the proposed method were validated by conducting recovery experiments on each medicinal crop sample fortified with cyanazine at two concentration levels per crop in triplicate. Conclusions: The mean recoveries ranged from 91.2% to 105.3% for the four representative medicinal crops. The coefficients of variation were less than 10%, irrespective of the sample types and fortification levels. The limit of quantification of cyanazine was 0.02 mg/kg as verified by the recovery experiment. A confirmatory method was performed by liquid chromatography/MS using selected-ion monitoring technique to clearly identify the suspected residue.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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• pp.36.2-36.2
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• 2009

We present GALEX (Galaxy Evolution Explorer) far (FUV) and near (NUV) ultraviolet imaging of 34 nearby early-type galaxies from the SAURON representative sample of 48 E/S0 galaxies, all of which have ground-based optical imaging from the MDM Observatory. The surface brightness profiles of nine galaxies (~26 per cent) show regions with blue UV-optical colours suggesting recent star formation. Five of these (~15 per cent) show blue integrated UV-optical colours that set them aside in the NUV integrated colour-magnitude relation. These are objects with either exceptionally intense and localised NUV fluxes or blue UV-optical colours throughout. They also have other properties confirming they have had recent star formation, in particular Hbeta absorption higher than expected for a quiescent population and a higher CO detection rate. This suggests that residual star formation is more common in early-type galaxies than we are used to believe. NUV-blue galaxies are generally drawn from the lower stellar velocity dispersion (sigma_e <200 km/s) and thus lower dynamical mass part of the sample. We have also constructed the first UV Fundamental Planes and show that NUV blue galaxies bias the slopes and increase the scatters. If they are eliminated the fits get closer to expectations from the virial theorem. Although our analysis is based on a limited sample, it seems that a dominant fraction of the tilt and scatter of the UV Fundamental Planes is due to the presence of young stars in preferentially low-mass early-type galaxies.

• 한국식품과학회지
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• 제29권3호
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• pp.412-416
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• 1997

7개의 국내 시판 사과 주스제품에 대해 patulin 오염수준을 분석하였다. Sep-Pak silica cartridge를 이용한 ethyl acetate 추출물의 정제과정은 HPLC 분석시 추출물내의 다른 성분으로부터 patulin의 분리를 용이하게 하였다. Patulin 검출은 J'sphere $4\;{\mu}m$ ODS-H80 column을 사용하여 reverse phase HPLC로 274 nm에서 분석하였다. 분석결과 4개의 제품은 $4{\sim}20\;{\mu}g/L$ 수준으로, 나머지 3개 제품은 $30{\sim}45\;{\mu}g/L$ 수준으로 patulin에 오염되어 있었다. 이 분석방법에서의 검출 한계농도는 $3\;{\mu}g/L$이며 $3.78{\sim}125.9\;{\mu}g/L$ 오염수준에 대해 $80{\sim}90%$의 회수율을 보였다.

• Bulletin of the Korean Chemical Society
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• 제30권7호
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• pp.1470-1474
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• 2009

Thermal and photochemistry of methyl iodide ($CH_3I)\;adsorbed\;on\;D_2O$ ice film on Cu(111) at 100 K were studied using temperature-programmed desorption (TPD) time-of-flight mass spectrometry (TOF-MS), X-ray and ultraviolet photoelectron spectroscopies. On the basis of TPD, multilayer and monolayer $CH_3I$ molecules desorb from $D_2O$ ice layer at 120 and 130 K, respectively. Photo-irradiation at 100 K exhibits dramatic changes in the TPD and I $3d_{5/2}\;XPS\;of\;CH_3I$ on ice film, due to a dramatic dissociation of $CH_3I$. The dissociation is likely activated by solvated electrons transferred from the metal substrate during photo-irradiation. No other photo-initiated reaction products were found within our instrumental detection limit. During photo-irradiation, the $CH_3I$, $CH_3$ and I could be trapped (or solvated) in ice film by rearrangement (and self-diffusion) of water molecules. A newly appeared parent molecular desorption peak at 145 K is attributed to trapped $CH_3I$. In addition, the $CH_3$ and I may diffuse through ice and chemisorb on Cu(111), indicated by TPD and I $d_{5/2}$ XPS taken with photo-irradiation time, respectively. No molecular ejection was found during photo-irradiation at 100 K. The work functions for $CH_3I/Cu(111),\;D_2O/Cu(111)\;and\;CH_3I/D_2$O/Cu(111) were all measured to be about 3.9 eV, 1.0 eV downward shift from that of clean Cu(111).

• Archives of Pharmacal Research
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• 제24권4호
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• pp.307-311
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• 2001

The activation of NF-$\kappa$B induced by kojic Acid, an inhibitor of tyrosinase for biosynthesis of melanin in melanocytes, was investigated in human transfectant HaCaT and SCC-13 cells. These two keratinocyte cell lines transfected with pNF-$\kappa$B-SEAP-NPT plasmid were used to determine the activation of NF-$\kappa$B. Transfectant cells release the secretory alkaline phosphatase (SEAP) as a transcription reporter in response to the NF-$\kappa$B activity and contain the neomycin phosphotransferase (NPT) gene for the dominant selective marker of geneticin resistance. NF-$\kappa$B activation was measured in the SEAP reporter gene assay using a fluorescence detection method. Kojic Acid showed the inhibition of cellular NF-$\kappa$B activity in both human keratinocyte transfectants. It could also downregulate the ultraviolet ray (UVR)-induced activation of NF-$\kappa$B expression in transfectant HaCaT cells. Moreover, the inhibitory activity of kojic Acid in transfectant HaCaT cells was found to be more potent than known antioxidants, e.g., vitamin C and N~acetyl-L-cysteine. These results indicate that kojic Acid is a potential inhibitor of NF-$\kappa$B activation in human keratinocytes, and suggest the hypothesis that NF-$\kappa$B activation may be involved in kojic Acid induced anti-melanogenic effect.

• Archives of Pharmacal Research
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• 제19권6호
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• pp.529-534
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• 1996

A high-performance liquid chromatographic (HPLC) assay has been developed for the determination of ketorolac in human serum using a new extraction method with a good recovery. Human serum samples (1.0 ml) spiked with known concentrations of ketorolac tromethamine and 10${\mu}g$ of ketoprofen as the internal standard (IS) were acidified with 200${\mu}l$ of 1 N HCl and extracted with 7 ml of n-hexane-ether (7:3 v/v). Extracts were centrifuged and organic layer was back-extracted with 400${\mu}l$ of 0.1% tromethamine solution. Twenty .mu.l of centrifuged aqueous layer was injected onto a reversed-phase octyl column and eluted with a mixture of acetonitrile, water, methanol, and triethylamine [35:55:10:0.1 (v/v), pH 3.0] at a flow rate of 1.0 ml/min. Ultraviolet detection of ketorolac and IS was carried out at 300 nm. The calibration curve obtained using peak area ratios showed a good linearity (in concentration range 10-150 ng/ml $r^2$=O.9944; in range 50-2000 ng/ml, r$^{2}$=0.9998). The mean intra-day accuracy and precision for this HPLC method were found to be 3.6 and 3.7%, respectively. The mean inter-day accuracy and precision were found to be 4.0 and 3.7%, respectively, in the concentration range 50-2000 ng/ml. The recovery of ketorolac from serum was 92.0 $({\pm}5.7)$ % at the concentration of 100 ng/ml. This method proved to be readily applicable to the assay of ketorolac in human serum.

• 한국작물학회지
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• 제51권1호
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• pp.95-100
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• 2006

Sesamin and sesamolin, antioxidant lipidsoluble lignan compounds, are abundant in sesame (Sesamum indicum L.) seed oil and provide oxidative stability of oil related to sesame quality. The sesamin and sesamolin contents of 403 sesame land races of Korea were determined by HPLC analysis of methanol extract (HPLC value), and their total lignan content was compared with those by using UV-Vis spectrophotometric analysis (UV method) of methanol (UV-MeOH value) and hexane (UV-Hexane value) extracts. HPLC values of total lignan content were strongly associated with UV-Hexane (r=0.705**) and UV-MeOH (r=0.811**) values. The UV values from both the extracts were 3.8-4.7 times higher than those of HPLC values. Lignan content was overestimated by UV method because total compounds in the mixture solution were quantified by absorbing at the same ultraviolet wavelength as in HPLC method. UV method could more rapidly analyze small amount of sample with higher sensitivity of detection than HPLC method. Average contents of lignans in sesame germplasm evaluated in this study were $2.09{\pm}1.02mg/g$ of sesamin, and $1.65{\pm}0.61mg/g$ of sesamolin, respectively, showing significant variation for lignan components. The results showed that UV method for the determination of sesamin and sesamolin could be practically used as a faster and easier method than HPLC by using the regression equations developed in this study.

• Journal of Electrical Engineering and Technology
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• 제9권5호
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• pp.1704-1711
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• 2014

Sandy and dusty weather condition often occurs in the high altitude areas of China, which may greatly influence the corona generated radio interference (RI) characteristics of the bundle conductors of 750 kV AC power transmission lines. Corona generated RI of the conductors of the 750 kV AC power transmission lines used in practice is measured by EMI receiver with a coupling circuit and a coupling capacitor connected between the high voltage side and the earth side in fine and sandy and dusty condition. The measuring frequency is 0.5 MHz, and the quasi-peak detection is used. RI excitation function is calculated based on the corona RI current measured by the EMI receiver. Corona generated RI characteristics were analyzed from sand concentration and sand particle size. The test result shows that the corona generated RI excitation function is influenced by the sandy and dusty condition. Corona discharge of the conductors is more serious in sandy and dusty condition with an ultraviolet (UV) detector. Corona generated RI excitation function increases with the increase of sand concentration and also increases with the increase of particle size.