• Analytical Science and Technology
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• v.8 no.3
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• pp.229-236
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• 1995

Multiple-step gradient method was used for the analysis of free amino acids in physiological fluids by high-performance liquid chromatography with diode array detector on the Amino Quant $C_{18}$ column under the condition of pH 7.2 of buffer solutions. Plasma samples of normal Korean people and abnormal Korean people who have schizophrenia were subjected to derivatization with o-phthalaldehyde in the presence of 3-mercaptopropionic acid. Quantitative analysis of amino acids in physiological fluids by internal standard method gave highly reproducible results within a relative standard deviation of less than 2~6%. And amino acids amounts of physiological fluids of Korean people gave some different results from those of foreigners. There was large differences in tyrosine amount between normal and abnormal man.

• Journal of fish pathology
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• v.20 no.2
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• pp.139-145
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• 2007

To decrease stress in eel (Anguilla japonica) during its culture or transportation, aspirin (ASA) known as analgesic, antiinflammatory and antithrombic agent was administrated by dipping or oral routes. Concentrations of aspirin (ASA) and salicylic acid (SA) in eel plasma were simultaneously measured by a high performance liquid chromatography (HPLC). The plasma was acidified with 0.2 M HCl and 0.2 M orthophosphoric acid, and mixed with acetonitrile. ASA and SA extracted with acetonitrile were analyzed by the HPLC equipped with reversed phase Novapak C18 column (4 ㎛ silica, 150×4 mm) and UV detector(237 nm). The mobile phase consisted of 740 ㎖ water, 900 ㎕ orthophosphoric acid (85%) and 180 ㎖ acetonitrile. The retention times of ASA, SA and 2-methylbenzoic acid(MBA) were 4.8 min, 8.4 min and 11.5 min, respectively. The limit of quantification was 0.01 ㎍/㎖ for SA and 0.05 ㎍/㎖ for ASA. The mean recovery from eel plasma was 70.8～99.6% for ASA and 95.2～100.3% for SA. This HPLC method was applied to analyze ASA and SA of eel plasma after either dipping in a concentration of 20 ppm or feeding the feed supplemented with 50 ㎎/kg BW. Only SA was detected in eel plasma after the administration of ASA by dipping or oral routes because the drug was quickly decomposed into SA in eel plasma. The amount of SA in eel plasma reached the highest value at 3hr in dipping and 7 days in oral administration. When the ASA-administrated eel were kept in ASA free aquaria, 0.02-0.03 ㎍/㎖ of SA were detected 48 hr after the administration in both routes.

• The Korea Journal of Herbology
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• v.28 no.5
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• pp.95-101
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• 2013

Objectives : A quantitative method using high performance liquid chromatography with a photodiode array detector(HPLC-PDA) was established for the quantitative analysis of the four main compound and pattern analysis to classification Piiellia ternate, P. pedatisecta and Typhonium flagelliforme. Methods : The analytical procedure for the determination of P. ternata, together with the known main compounds uracil, uridine, guanosine and adenosine was established. Optimum HPLC-PDA separation of these P. ternata was possible on Luna C18(2) column material, using water and acetonitrile as mobile phase. The method was validated according to regulatory guidelines. In addition, this assay method were analyzed for the content of four main compound in P. ternata, P. pedatisecta and T. flagelliforme and by data obtained from the HPLC-PDA analysis was performed principal component analysis(PCA). Results : Validation results indicated that the HPLC method is well suited for the determination of the roots of P. ternata with a good linearity ($r^2$ > 0.999), precision and recovery rates. Analysis of HPLC-PDA, the average content of uracil, uridine, guanosine and adenosine was significantly higher in P. ternate>P. pedatisecta> T. flagelliforme order. The application of PCA to main compound data by HPLC-PDA permitted the effective discrimination among the three species. Conclusions : Analysis of both HPLC-PDA and PCA confirmed the fact that four main compound and pattern profiles of P. ternata, P. pedatisecta and T. flagelliforme were different from each other.

• Journal of the Korean Society of Tobacco Science
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• v.27 no.1 s.53
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• pp.114-119
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• 2005

The study was carried out to develope quantitative analysis method of individual sugars in licorice extract. Individual sugars were analyzed by HPLC equipped with Refractive Index(RI) Detector. R values of sucrose and glucose were 1.0000 and R values of fructose and maltose were 0.9999. Standard calibration curve showed good linearity. Detection limit of sugars was in the range of 1.58 to 3.92 ${\mu}g$. Recovery rate of fructose, glucose, sucrose and maltose was $99.4\~102.2\%,\;92.3\~97.9\%,\;99.4\~102.0\%,\;91.1\~101.0$ respectively. Measure uncertainty was calculated to confirm trust and accuracy of analytical results. Main uncertainty factors were standard purity and HPLC replication injection. In $95\%$ trust level expanded uncertainty of sugars in licorice extract were fructose $1.98\pm0.047,\;glucose\;1.32\pm0.065,\;sucrose\;11.69\pm1.177,\;maltose\;1.06\pm0.042\;g/100\;g$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.5
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• pp.319-324
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• 2005

This study was conducted to identify the soluble carbohydrates in soybean seeds using on-line HPLC-RID-ES/MS and HPLC behavior, and to deter­mine their contents for high quality soybean breeding. The monosaccharide (glucose) and three oligosaccharides (sucrose, raffinose, and stachyose) were identified in Korean soybeans by their chromatographic behavior and results of on-line HPLC-RID-MS with Electro­spray Ionization mode. On the basis of HPLC with a RID detector, the 32 Korean major soybeans contain $0.37{\pm}0.26\%$ glucose, $4.55{\pm}0.91\%$ sucrose, $1.19{\pm}0.19\%$ raffinose, and $2.72{\pm}0.37\%$ stachyose on a dry basis. In 468 soybean germplasms, the ranges of glucose, sucrose, raffinose, and stachyose were $0.03 - 0.98\%$, $2.33 - 6.96\%$, $0.08 -1.87\%$ and $0.75 - 3.18\%$, respectively. Among 500 soybean samples, oligosaccharide contents of 32 Korean major cultivated soybeans and 468 soybean germplasms were varied $5.83 - 10.06\%$ and $3.66 - 10.32\%$, respectively. The composition of glucose, sucrose, raffinose, and stachyose in soluble carbo­hydrates of 500 soybean samples were $2.07 {\pm} 1.75\%$, $58.01{\pm}5.82\%$, $10.13{\pm}2.28\%$ and $29.80{\pm}4.54\%$, respectively. Sucrose appeared to be most prevalent in soy­bean soluble carbohydrates.

• Korean Journal of Pharmacognosy
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• v.45 no.4
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• pp.294-299
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• 2014

The simultaneous determination of platyphylloside, aceroside and betulin was established for the quality control of Betula platyphylla bark using a high performance liquid chromatography and diode-array UV/Vis detector (HPLC-DAD). Separation and quantification were successfully achieved with a INNO C18 column ($5{\mu}m$, 4.6 mm $I.D.{\times}150mm$) by gradient elution of a mixture of methanol and water at a flow rate of 1.0 ml/min. Validation of the developed method was performed by various factor such as linearity, specificity, precision, accuracy, system suitability and stability. This method was successfully applied to the determination of contents of platyphylloside, aceroside VIII and betulin in three batches of Betula platyphylla bark extract. These results suggest that the developed HPLC method is simple, effective and could be utilized as a quality control method for Betula platyphylla bark products.

• Journal of Pharmaceutical Investigation
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• v.22 no.4
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• pp.317-321
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• 1992

A high-performance liquid chromatographic (HPLC) method was developed for the determination of diltiazem (DTZ) and its major metabolite, deacetyldiltiazem (DAD), in rat plasma. DTZ, DAD and imipramine, the internal standard, were selectively fractionated from plasma on a $C_{18}$ reversedphase column $({\mu}-Bondapak,\;10\;{\mu}m\;silica,\;300{\times}3.9\;mm\;ID)$. The composition of the mobile phase was methanol: acetonitrile: 0.04 M ammonium bromide: triethylamine (40:24:36:0.06 in volume). The pH of the mobile phase of their method was lowered to 6.4. The eluents from the column were detected for DTZ and DAD using a UV detector at 237 nm. The recovery was >85% for DTZ and DAD, and average intra-day and inter-day coefficients of variation were <6% for DTZ and DAD at the concentration ranges of 20-1000 ng/ml. Detection limit of DTZ and DAD in plasma was 20 ng/ml with signal-to-noise ratio of 3. This method would be applicable to practical pharmacokinetic studies without detriment to the HPLC column.

• Analytical Science and Technology
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• v.13 no.3
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• pp.282-290
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• 2000

In this study, polymer additives were extracted and separated by Soxhlet extraction method and the dissolution-precipitation method from a polycarbonate (optical grade) which completely absorbed UV light below 390 nm. Analytical techniques such as UV-Vis spectroscopy, FT-IR, and HPLC were applied to analyze additives in polycarbonate. Separated materials from the polycarbonate may be a complex mixture containing additives such as UV stabilizer, antioxidants (primary and secondary), monomers, and oligomers. Several compounds such as bisphenol A, Irganox 1010, and Cyasorb UV-5411 were identified by chromatograms and UV spectra obtained from RP HPLC analysis using Bondapak $C_{18}$ column, methanol mobile phase, and a photodiode array (PDA) detector. Also, the content of UV-5411 in the polycarbonate was about 0.12 wt% by a quantitative analysis through UV spectroscopy.

• Journal of Food Hygiene and Safety
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• v.13 no.4
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• pp.344-354
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• 1998

This study was conducted to evaluate the MSPD and HPLC method about simultaneous determination for residual synthetic antimicrobials of sixteen species such as sulfonamide etc. in livestock products. Elution solvent used in HPLC was ethylacetate:acetonitrile (4:1), and mobile phases for solvent A and B were water:methanol:acetonit rile:phosphric acid (700:250:50:0.2) and 100% acetonitrile respectively. The detector and absorbency used in HPLC was UV 266 nm. This study showed the reduction effect of 99.1% for organic solvents, 94% for experimental steps, 95% for analytical time and manpower and 98.9% for costs compared with korea food standard method. The average recovery rates for chicken, bovine, pork and milk were 67.7% 96.2%, 67.7%~96.6%, 70.0%~96.2%, and 13.8%~97.8%.

• Korean Journal of Veterinary Research
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• v.41 no.1
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• pp.13-19
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• 2001

A simple and rapid analytical method for the determination of tylosin in chicken, pork and muscle was established by High-Performance Liquid Chromatography(HPLC). Chicken, pork and beef muscle(5 g) were fortified by adding the $0.2{\mu}g/ml$ of standard tylosin and the drug was extracted from meats with 70% acetonitrile(ACN) and followed by liquid-liquid partition for clean-up procedure. Then $20{\mu}l$ portion of ACN elution was directly analyzed by HPLC with spectra 100 variable wavelength detector, and unfortified blank control were treated similarly. The average recovery rate of tylosin added to chicken, pork and beef muscle were $83{\pm}2.3$, $96{\pm}3.3$ and $92{\pm}1.6$(%) at the level 0.2 ppm, respectively. No tylosin residues in marketing meats. These results suggested that HPLC methodology could be acceptable for the extraction, determination and screening of tylosin residues in edible meats.