• Proceedings of the PSK Conference
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• 2001.10a
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• pp.315.2-315.2
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• 2001

• Applied Biological Chemistry
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• v.39 no.1
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• pp.84-88
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• 1996

To determine brassinolide in rice(Oriza sativa L.) using HPLC equipped with fluoresence detector, a highly sensitive fluorescence reagent. 1-cyanoisoindole-2-m-phenylboronic acid, was synthesized from the reaction of o-phthaldehyde, m-phenylboronic acid and KCN, then was reacted with brassinolide. The formation ratio of brassinolide boronate exhibited 90% up at the ratio of $20\;:\;1({\mu}g/{\mu}g)$ of 1-cyanoisoindole-2-m-phenylboronic acid and brassinolide respectively. The detection limit of brassinolide boronate with fluoresence detector was 0.16 ng. Brassinolide was detected in heading stage(biomass : 10 g) and panicle formation stage(biomass : 100 g) of the rice(Oryza sativa L.) with quantity of $0.8\;{\mu}g\;and\;0.2\;{\mu}g$respectively. However, brassinolide was not detected in blooming and elongation stage.

• Analytical Science and Technology
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• v.7 no.3
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• pp.413-419
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• 1994

The determination of the neuromuscular blocking agents vecuronium bromide(VeBr) in biological fluids has been investigated. The method depends on the formation of insoluble red complex between vecuronium bromide and rose bengal in aqueous layer. The amount of vecuronium bromide was calculated from that of extracted rose bengal which was determined by spectrofluorimetry or HPLC/fluorescence detection method. It was possible to analyze VeBr in the range of $2{\sim}32{\mu}g/ml$(r=0.998 for water soln., 0.999 for urine, 0.996 for plasma). This method was applied to the analysis of VeBr in biological fluids, urine and plasma.

• Toxicological Research
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• v.30 no.1
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• pp.7-11
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• 2014

Malondialdehyde (MDA), used as an oxidative stress marker, is commonly assayed by measuring the thiobarbituric acid reactive substances (TBARS) using HPLC, as an indicator of the MDA concentration. Since the HPLC method, though highly specific, is time-consuming and expensive, usually it is not suitable for the rapid test in large-scale environmental epidemiologic surveys. The purpose of this study is to develop a simple and rapid method for estimating TBARS levels by using a multiple regression equation that includes TBARS levels measured with a microplate reader as an independent variable. Twelve hour urine samples were obtained from 715 subjects. The concentration of TBARS was measured at three different wavelengths (fluorescence: ${\lambda}-_{ex}$ 530 nm and ${\lambda}-_{em}$ 550 nm; ${\lambda}-_{ex}$ 515 nm and ${\lambda}-_{em}$ 553 nm; and absorbance: 532 nm) using microplate reader as well as HPLC. 500 samples were used to develop a regression equation, and the remaining 215 samples were used to evaluate the validity of the regression analysis. The induced multiple regression equation is as follows: TBARS level (${\mu}M$) = -0.282 + 1.830 ${\times}$ (TBARS level measured with a microplate reader at the fluorescence wavelengths ${\lambda}-_{ex}$ 530 nm and ${\lambda}-_{em}$ 550 nm, ${\mu}M$) -0.685 ${\times}$ (TBARS level measured with a microplate reader at the fluorescence wavelengths ${\lambda}-_{ex}$ 515 nm and ${\lambda}-_{em}$ 553 nm, ${\mu}M$) + 0.035 ${\times}$ (TBARS level measured with a microplate reader at the absorbance wavelength 532 nm, ${\mu}M$). The estimated TBARS levels showed a better correlation with, and are closer to, the corresponding TBARS levels measured by HPLC compared to the values obtained by the microplate method. The TBARS estimation method reported here is simple and rapid, and that is generally in concordance with HPLC measurements. This method might be a useful tool for monitoring of urinary TBARS level in environmental epidemiologic surveys with large sample sizes.

• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.23-28
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• 2004

We established a new method to analyze moxidectin using high performance liquid chromatography(HPLC) with fluorescence derivatization in order to obtain its residual profiles in biological samples. Recovery of moxidectin in tissue was 62% at 10 ppb. Average detection reproducibility in terms of coefficience variation was 4.47% at 0.32 to 10 ppb. Residual of moxidectin was studied in 44 Yorkshire-Landrace mixed bred male pigs administered subcutaneously 0, 200, or $800{\mu}g/kg$ body weight (BW) Residual profiles of moxdectin in blood, muscle, liver, kidney and fat of pigs were described. The concentration of the moxidectin in liver after administration of moxidectin was the highest among the tissues examined. Moxidectin in liver after administration of moxidectin as $200{\mu}g/kg$ BW was declined from $10.0{\pm}3.7ng/g$ at 10 day post administration to $0.5{\pm}0.3ng/g$ level at 40 day post administration. Residual levels of moxidectin in all samples were estimated to fall below the limit of quantitation (0.32 ng/ml) after 50 day after treatment of $200{\mu}g/kg$. Moxidectin showed no abnormal observations in all the clinical findings at any concentrations under these experimental conditions. In conclusion, this analysis method by HPLC after fluorescence derivatization was very effective for the detection of moxidectin in biological samples. We suggest that 50-day is safe enough for the withdrawal time of moxidectin in pigs, following the recommendation dose by the manufacturer.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2727-2731
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• 2011

A new method for the determination of josamycin has been developed based on quenching of the fluorescence of 3-mercaptopropionic acid-capped CdTe quantum dots (MPA-CdTe QDs) by josamycin in ethanol. Reaction time, interfering substances on the fluorescence quenching, and mechanism of the interaction of CdTe QDs with josamycin were investigated. Under optimum conditions, the relative fluorescence intensity was linearly proportional to the concentration of josamycin between 12.0 and 120.0 ${\mu}g\;mL^{-1}$ with a correlation coefficient of 0.9956 and a detection limit of 2.5 ${\mu}g\;mL^{-1}$. The proposed method was successfully applied to commercial tablets, and the results were satisfactory, i.e. consistent with those of high-performance liquid chromatography (HPLC).

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.3
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• pp.312-321
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• 2015

Objectives: The purpose of this study was to determine the best method to analyze PAHs at extremely low concentrations. To this end, 16 PAHswere analyzed simultaneously by GC/MS, HPLC/FLD and HPLC/UVD, and the analytical characteristics of HPLC and GC/MS were compared. Methods: This study was conducted by GC/MS and HPLC/FLD/UVD, and evaluated linearity, precision and detection limit. Standard solutions were prepared for 21 samples in the range of $0.00001{\sim}1.0{\mu}g/mL$ and the samples were divided into four groups. All samples were made in three sets and analysis was replicated seven times. Results: Sixteen PAHs could be simultaneously separated by HPLC and GC/MS, and the adequate equipment was HPLC/FLD. The retention times by HPLC were shorter than GC/MS, and HPLC had better separation for most PAHs than GC/MS. The peaks of naphthalene and naphthalene-D8 partially overlapped for GC/MS. HPLC/FLD had a 20-2000 times lower limit of detection than GC/MS and UVD. However FLD was not adequate for analyzing acenaphthylene because it has too low a fluorescence quantum yield to be detected. The precision of HPLC/FLD/UVD and GC/MS showed less than 20% at $0.001{\mu}g/mL$ PAHs and when the concentration was higher, the coefficient of variation was decreased. HPLC/FLD was better for the overall detection of limits. Conclusions: The results indicate that the HPLC/FLD method has good linear range, precision and a detection of limits from $0.00001{\sim}0.0001{\mu}g/mL$ for all 16 PAHs. This study contributes to providing useful data for analysis technology and can be applied to occupational exposure measurement for PAHs in workplaces.

• YAKHAK HOEJI
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• v.38 no.4
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• pp.379-388
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• 1994

A new method for the analysis of metocurine iodide in biological fluids was developed. Metocurine iodide was quantitatively extracted with rose bengal from aqueous layer into dichloromethane layer and the amount of metocurine iodide was calculated from the amount of rose bengal which was determined by HPLC with fluorescence detector. It was possible to analyze metocurine iodide without the effect of co-prescribed drugs in the concentration range of $0.09{\sim}9.10\;{\mu}g/ml$. The detection limits of metocurine iodide in urine and blood were 0.8 and 1.2 ng at S/N=3, each respectively.

• Archives of Pharmacal Research
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• v.17 no.5
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• pp.337-342
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• 1994

Carbohydrate analysis is important in studying structure and activity of complex polysaccharides. New analytical method was applied to get an information on the composition of polysaccharides showing antitumor activity. Monosaccharides were labeled with 7-amino-1, 3-naph-thalenedisulfonic acid (7-AGA) by reductive amination and separated by HPLC. Five kinds of polysaccharides from Basidiomycetes were hydrolyzed and analyzed in combination with electrophresis and HPLC. At the same time, alditol acetate derivatives were prepared and analyzed by gas chromatography. Two different techniques using different derivatization methods showed very similar results. The monosaccharides from Coriolus versicolor and Cordyceps militaris were glucose and galactose. Phellinus linteus composed of glucose, glactose, mannose, arabinose and fucose. The HPLC method with fluorescence detector was very sensitive compared to other methods.

• Korean Journal of Veterinary Research
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• v.47 no.4
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• pp.389-393
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• 2007

In this study, the levels of aflatoxin $M_1$ ($AFM_1$) in milk were determined by HPLC with derivatization method. Milk samples were purified using $C_{18}$ disposable cartridge followed by derivatization with trifluoroacetic acid and analysed using HPLC with fluorescence detection. The recoveries of AFM1 from milk samples added $AFM_1$ at a level of 0.025~0.1 ng/ml were 94.7~98.0% with detection limit of 0.009 ng/ml. The amounts of $AFM_1$ were determined below 0.05 ng/ml for all tested samples of commercial milk collected in 1999 and 2000.