• 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.

• Journal of Preventive Medicine and Public Health
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• v.20 no.2 s.22
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• pp.215-220
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• 1987

Under the extreme change of the environment, animals react physiologically to adapt to the stress and secrete catecholamines. Cold exposure is a kind of the environmental stress. Author tried to determine the amount of catecholamines in rat urine as a parameter of physiological response to cold stress. Urinary catecholamine was measured by using HPLC with fluorescence detector, cation exchange column prepacked with Bio·Rex 70 and ammonium pentaborate as catecholamine eluent. The amount of dopaminc in normal state rat urine was 42.0 ng, but under the low temperature of $5^{\circ}C$, the dopamine amount was increased to 221.25 ng/5 ml. Above findings are suggesting that catecholamine secretion, especially dopamine, increases in the stressful condition such as cold exposure.

• Analytical Science and Technology
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• v.30 no.1
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• pp.20-25
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• 2017

An analytical method for determining potential endocrine disruptors (bisphenol A, 2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, pentachlorophenol, p-t-butylphenol, p-pentylphenol, p-hexylphenol, p-t-octylphenol, p-heptylphenol, nonylphenol) by solid-phase extraction (SPE) and High Perfomance Liquid Chromatography(HPLC) equipped with fluorescence and variable wavelength detector has been developed. The SPE process for sample concentration was performed on a commercially available Oasis HLB cartridge packed with polymeric sorbents. The effect of elution solvent and elution volume on the recoveries of the analytes were investigated with HPLC. Average recovery of >85% was achieved with 60mg sorbents using 5mL of methanol as elution solvent. Phenolic compounds in canned drinks, beverages and water samples were surveyed by this proposed method.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1515-1518
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• 2009

The objective of this study was to compare 3 extraction methods including, solid phase extraction (SPE), acetonitrile extraction, and methanol extraction, for their usefulness as extraction methods to determine capsaicinoids. The determination of capsaicinoids in the extracts was carried out on a reverse-phased high performance liquid chromatography (HPLC) using a fluorescence detector. Three extraction methods, i.e., SPE, acetonitrile extraction, and methanol extraction were compared for the quantification of capsaicinoids using raw peppers and pepper powder. The highest analytical values were observed using methanol extraction and the lowest values using SPE. Also, the analytical method validation parameters such as accuracy, precision, limit of detection, limit of quantitation, and specificity were calculated to ensure the method's validity. This method provides a fast and accurate approach for the determination of capsaicinoids in peppers.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.16 no.1
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• pp.40-46
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• 1990

A method was described for the analysis of Artemisia extract in cosmetic soap. Esculetin-6-methylether was used as indicator ingredient for analysis of Artemisia extract. It was isolated from the plant and purified with silicagel column. The structure was conformed with IR, NMR and MASS spectroscopy. The Artemisia extract in sample was isolated with chloroform and interfering com- pounds were eliminated with silicagel column. The Artemisia extract was determined by reverse phase high- performance liquid chromatography with a fluorescence detector and a solvent system of H2O/THF/MeOH. The recorveries of Artemisia extract were 93.9-106.1% in the cosmetic soap.

• Journal of the Korean Vacuum Society
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• v.20 no.6
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• pp.409-415
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• 2011

The method to improve the detection sensitivity of Hand-held XRF (X-Ray Fluorescence) device currently being developed is discussed. To minimize the loss of the intensity due to atmospheric gas molecules, the vacuum module, which can be filled with atmospheric or He gas, between the sample and the detector was installed. And the change of the detection sensitivity was measured in a vacuum and in the He gas-filled state. As a result, the following three important results were obtained; Firstly, XRF intensity was increased 2~4 times in the low energy range (3~4 keV). It is a very important result because the enhancement of the detection sensitivity means shortening of the detection time in Hand-held XRF device. Secondly, the possibility of detection of the elements less than 3 keV in emission energy was confirmed. Thirdly, the absorption by atmospheric gas molecules can be minimized without vacuum- sealed vessel in Hand-held XRF device, if the vacuum module filled with He gas is used. We concluded that all of three results are very meaningful in the development of a Hand-held XRF device.

• Journal of Food Hygiene and Safety
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• v.19 no.1
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• pp.12-18
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• 2004

Ofloxacin, norfloxacin, ciprofloxacin, and enrofloxacin in chicken muscle were seperated by liquid extraction and determined with high performance liquid chromatography (HPLC) with fluorescence detector. Analysis was carried out using following conditions; Cl8 column (250${\times}$4.6 mm i.d. 5 ${\mu}{\textrm}{m}$ particle size), mobile phase composed of D.W. (containing 0.4% triethylamine and phospholic acid): methanol : acetonitrile (800:100:100, v/v/v), isocratic pump at a flow rate of 1.0 $m\ell$/min and 50 ${mu}ell$ of injection volume, fluorescence detector with EX278 nm/EM.456 nm. The calibration curves of four fluoroquinolones showed linearity (${\gamma}$$^2$$\geq$0.999) at concenration range of 0.025-0.6 $\mu\textrm{g}$/ml. The recoveries in fortified chicken muscle represented more than 80% with low coefficient of variation (〈10%) for concentration range of four fluoroquinolones. The detection limits for ofloxacin, norfloxacin, ciprofloxacin, and enrofloxacin were 23.5, 3.4, 3.0 and 2.5 ng/g in chicken muscle, respectively. We also monitored fluoroquinolones residue in muscle of chickens (broiler 1:227, Korean native chicken 219, laying chicken 77) using EEC-4-plate screening and HPLC conformation methods. Ten(broiler 5, Korean native chicken 5) out of the fifteen samples which were positively detected by EEC-plate screening method from 1,523 chicken meat were confirmed with ciprofloxacin and enrofloxacin by HPLC. The ranges of residual concentration were 0-0.12 ppm for ciprofloxacin and 0.01-6.79 ppm for enrofloxacin. In conclusion, our method could be applied effectively to determine four fluoroquinolones residues in chicken meat, and further survey for fluoroquinolones residue in chicken meat are needed for more effective control of fluoroquinolones used in livestock.

• Journal of Pharmaceutical Investigation
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• v.40 no.1
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• pp.51-57
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• 2010

Losartan potassium, 2-butyl-4-chloro-1-[p-(o-1H-tetrazol-5-ylphenyl)benzyl]imidazole-5-methanol mono-potassium salt, is a new class of antihypertensive agents, and is an antagonist in angiotensin receptor. The purpose of the present study was to evaluate the bioequivalence of two Losartan potassium tablets, Cozaar tablet (MSD Pharmaceutical Co., Ltd.) and Losata tablet (Kyung Dong Pharmaceutical Co., Ltd.), according to the guidelines of the Korea Food and Drug Administration (KFDA). The release of losartan from the two losartan potassium formulations in vitro was tested using KP VIII Apparatus II method with various dissolution media. Twenty eight healthy male subjects, $23.86{\pm}1.80$ years in age and $67.27{\pm}6.60\;kg$ in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After a single tablet containing 50 mg as losartan potassium was orally administered, blood samples were taken at predetermined time intervals, and the concentrations of losartan in serum were determined using HPLC with fluorescence detector. The dissolution profiles of two formulations were similar in all tested dissolution media. The pharmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were calculated, and Equiv Test/K-BE Test 2002 was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$, $C_{max}$ and untransformed $T_{max}$. The results showed that the differences between two formulations based on the reference drug, Cozaar, were -2.70%, 1.45% and 2.31% for $AUC_t$, $C_{max}$ and $T_{max}$, respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log 0.8 to log 1.25 (e.g., log 0.8852~log 1.0655 and log 0.8319~log 1.2342 for $AUC_t$ and $C_{max}$, respectively). Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Losata tablet was bioequivalent to Cozaar tablet.

• Biomedical Science Letters
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• v.3 no.1
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• pp.29-35
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• 1997

Cardiovascular disease has been the leading cause of death among patients with chronic renal failure. Many reports have been described that homocysteine is one of the independent risk factor to the occulsive vascular disease. In this study, HPLC/FLD (high performance liquid chromatography-fluorescence detector) technique was used to measure homocysteine level in patients with chronic renal failure and normal control group. The detection limit and recovery of total plasma homocysteine using HPLC/FLD were 98.6$\pm$5.8% and 0.2 nmol/ml, respectively. The linearity of this method was established in concentration range of 2~50 nmol/ml (correlation coefficient=0.9997). The concentrations of total plasma homocysteine were 6.81$\pm$1.54 nmol/ml and 27.28$\pm$14.94 nmol/ml in normal control (n=20) and patient group (n=90), respectively (p<0.05). In this study, the HPLC/FLD method showed high sensitivity and reproducibility for a routine clinical laboratory testing. Moreover determination of homocysteine level in plasma might be useful for a biochemical marker for predicting the cardiovascular diseases and for monitoring of therapeutic effect of lowering homocysteine in patients with chronic renal failure.

• Analytical Science and Technology
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• v.23 no.2
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• pp.196-204
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• 2010

In this study, the following concentrations of some PAHs (Polycyclic Aromatic Hydrocarbons) were investigated; [benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene, indeno(1,2,3-c,d)pyrene] in processed foods (n=165) and cooked meats (n=45) and established the analytical method by characteristics of processed foods. The methodology involved extraction (alkali digestion, liquid-liquid extraction, microwave extraction), clean-up on Sep-Pak Florisil Cartridges and determination by HPLC/FLD (High Performance Liquid Chromatography/Fluorescence Detector). The recovery of overall method for 8 PAHs spiked into these products ranged from 92 to 103%. The mean level of detected foods was found to be benzo(b)fluoranthene $0.9\;{\mu}g/kg$ in smoked salmon, benzo(b)fluoranthene $1.0\;{\mu}g/kg$, benzo(k)fluoranthene $0.3\;{\mu}g/kg$, benzo(a)pyrene $0.9\;{\mu}g/kg$ in dried banana, benzo(b)fluoranthene $0.2\;{\mu}g/kg$, benzo(k)fluoranthene $0.1\;{\mu}g/kg$, benzo(a)pyrene $0.2\;{\mu}g/kg$ in smoked chicken, benzo(b)fluoranthene $1.3\;{\mu}g/kg$, benzo(k)fluoranthene $0.3\;{\mu}g/kg$, benzo(a)pyrene $0.9\;{\mu}g/kg$ in charcoal grilled pork, respectively.