• YAKHAK HOEJI
• /
• v.55 no.4
• /
• pp.277-283
• /
• 2011

Simultaneous monitoring of catecholamines and serotonin with their appropriate extraction from the biological samples is required in order to understand thoroughly the regulation of the central and peripheral nervous system. In the present research the segmented gradient elution with the solid phase extraction using a C18 cartridge rather than the previous isocratic elution with alumina extraction is successfully employed to determine norepinephrine (NE), epinephrine (E), dopamine (DA), serotonin (5HT), 3,4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindoleacetic acid (5HIAA) simultaneously within 20 minutes using 3,4-dihydroxyhydrocinnamic aicd as the internal standard (IS). Linearities were obtained in the concentration range between $5{\times}10^{-6}M$ and $1{\times}10^{-4}M$ for all 7 compounds with detection limits of 0.6~1.9 ${\mu}M$. The present HPLC/ECD method yielded reasonable accuracy (relative error; -1.4~1.1%) and precision (relative standard deviation; 0.4~1.9%) for 9 measurements of the standard solution consisting of NE, E, DA, 5HT, DOPAC and 5HIAA compounds. Recoveries of catecholamines, serotonin and their metabolites from human serum were in the range of 57%~86%. While the concentrations of NE and 5HT in the serum of normal Sprague-Dawley rat were found as $1.4{\times}10^{-6}M$ and $2.6{\times}10^{-6}M$, respectively, the contents of NE and 5HT in the serum of the stressed rat were increased 5.6 times and 1.4 times more, respectively.

• Korean Chemical Engineering Research
• /
• v.49 no.6
• /
• pp.829-834
• /
• 2011

Lysozyme in egg white functions as bacteriolysis agent and ovalbumin plays a role as antigen in immune system. Egg white analysis methods usually include electrophoresis, gel permeation chromatography and reversed-phase HPLC(RP-HPLC). Among them, RP-HPLC was selected for rapid analysis and C18 column(Agilent, USA) was used as HPLC column. Optimum conditions were searched by changing mobile phase and temperature. Capacity factor and resolution were calculated and compared for various elution conditions. In the isocratic elution, mobile phase volume ratio was changed from 30/70/0.1 to 60/40/0.1(Acetonitrile(ACN)/Distilled water(DW)/Trifluoroacetic acid(TFA)). ACN composition was increased by 10% and temperature was set as $20^{\circ}C$. In the gradient elution, ACN/DW ratio was changed from 10/90 to 60/40 during 20 minute and temperature was varied as 20, 30 and $40^{\circ}C$. In the isocratic elution, three peaks were separated at 50/50/0.1. Lysozyme and ovalbumin were confirmed as first and third peak in three peaks respectively. In the gradient elution, four peaks were separated at $30^{\circ}C$. Lysozyme and ovalbumin were confirmed as first peak and third peak in four peaks respectively.

• Bulletin of the Korean Chemical Society
• /
• v.15 no.1
• /
• pp.74-77
• /
• 1994

Rare earth elements (REE) were individual separated by applying the gradient elution via HPLC using ${\alpha}-hydroxyisobutyric$ acid (HIBA) as an eluent. However, the overlap of Y and Dy peaks was too severe to obtain the resolution of these two peaks. The target transformation factor analysis (TTFA) was applied to resolve the elution peaks of Y and Dy. [A]$_{raw}$ formed from the absorbances of mixed solution was factor analyzed. The abstract factor analysis(AFA) was used to determine the number of components that contributed to the poorly resolved peaks. The error theory in the AFA showed that the number of components was 2. The test vectors which correspond to pure component were selected from the standard solutions of Y and Dy. TTFA was accomplished by target testing. The results showed that the resolution of two peaks as well as the determination of Y and Dy were possible by the factor analysis.

• Korean Journal of Food Science and Technology
• /
• v.20 no.6
• /
• pp.856-861
• /
• 1988

A new method developed for simultaneous purification of enterotoxin A and C from Staphylococcus aureus strain L 350/1 consisted of chromatography on carboxymethyl (CM)-cellulose using a buffer of variable pH, gel filtration on Ultro gel, and fast protein liquid chromatography(FPLC) using a buffer of variable pH. The enterotoxin A and C were purified by three steps: batchwise adsorption from culture supernatant on Amberlite CG-50; chromatography on CM-cellulose using a buffer of constant pH and molarity; and gel filtration on Sephadex G-75. The purified enterotoxin appeared homogeneous by gel diffusion and polyacrylamide gel electrophoresis. Upon treatment with CM-cellulose using a elution of variable pH, enterotoxin A and C were so close that they were not separated completely. After elution from gels, the enterotoxins appeared as a single peak at the same position. Gel filtration gave a reaction of complete identity to enterotoxin A and C in Ouchterlony immunodiffusion. In FPLC using a CM-cellulose, enterotoxin A and C were simultaneously separated at pH 8.6 and 6.8. When each fraction was performed to gel immunodiffusion, at peak of enterotoxin A and C were not detected each other. In a method of elution by pH-gradient was to be more efficient as a simultaneous separation method in terms of speed, yields and simplicity. The purified toxin A and C were identical to type A and C reference enterotoxin on both disc electrophoresis and Ouchterlony gel diffusion.

• Korean Journal of Food Science and Technology
• /
• v.33 no.3
• /
• pp.282-287
• /
• 2001

This study was carried out to investigate the difference of ginsenoside compositions in crude ginseng saponins prepared by five different methods including three new methods. Two known methods are hot methanol(MeOH) extraction/n-butanol(n-BuOH) fractionation and hot MeOH extraction/Diaion HP-20 adsorption/MeOH elution. Three new methods are hot MeOH extraction/cation AG 50W $absorption/H_2O$ elution/n-BuOH extraction, cool MeOH extraction/Diaion HP-20 adsorption/MeOH elution and direct extraction with ethyl acetate(EtOAc)/n-BuOH. Analysis of ginsenoside composition in the crude saponins by conventional HPLC/RI(Refractive Index) did not show great difference between methods except EtOAc/n-BuOH method. However, HPLC/ELSD (evaporative light scattering detector) employing gradient mobile phase afforded fine resolution of ginsenoside Rf, $Rg_1$ and $Rh_1$, and great difference of ginsenoside compositions between methods. LC/MS revealed that large amount of prosapogenins were produced during the pass through the cation exchange (AG 50W) column being strongly acidic. Six major ginsenosides such as $Rb_1,w;Rb_2,$ Rc, Rd, Re and $Rg_1$, 5 prosapogenins and one chikusetsusaponin were identified by LC/MS. A newly established HPLC method employing ODS column and gradient mobile phase of $KH_2PO_4/CH_3CN$ revealed that malonyl ginsenosides were detected only in the crude saponin obtained from cool MeOH extraction.

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.280.1-280.1
• /
• 2003

The high-performance liquid chromatography method was performed for test method development of related compounds in pharmaceuticals. Using reverse-phase column and gradient elution of 1 ％ acetonitrile-acetonitrile: H20:triethylamine (70:30:0.5), lansoprazole, 2-hydroxybenzimidazole, 2-mercaptobenzimidazole, lansoprazole sulfone, lansoprazole sulfide could be individually identified and quantitated. (omitted)

• Journal of Nutrition and Health
• /
• v.24 no.3
• /
• pp.199-205
• /
• 1991

Retinoic acid. the active metabolite of vitamin A. was detected in the human liver for the first time using a new method. A rapid and sensitive technique has been developed using gradient-elution. reverse-phase high performance liquid chromatography. This assay. with simultaneous multiwavelength detection at 294nm, 325nm and 450nm after saponifcation of liver samples. allows us seperation and quantitation of vitamin E, retinoic acid, total retinoids and various carotenoids in one small sample. The proportion of retinoic acid to total retinoids in human liver appears to be quite $consistent(2.4\pm0.2%$ ). With low vitamin A storage in liver, detection at another wavelenth 354nm would increase the sensitivity for retinoic acid of small quantity This method of analysis could be used for other tissues like red blood cells, plasma or serum, also. Hepatic retinoic acid level with total retinoids and carotenoids would serve a better indicator of functional vitamin A nutriture especially for those with disease requiring needle biopsy of liver.

• KSBB Journal
• /
• v.14 no.1
• /
• pp.109-113
• /
• 1999

Supercritical $CO_2$ chromatography was applied for purification of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish oil. Various supercritical $CO_2$ pressures were tested to find out the pressure effects on solubility and selectivity of low fatty acids in the silver nitrate column. The solubility of low fatty acids was increased as the supercntical $CO_2$ Pressure increased. However, the selectiviy between low fatty acids and EPA waw decreased. Stepwise density gradient method was applied to increase the purification efficiency of EPA. Low fatty acids were easily separated at the early elution steps with low $CO_2$ densities. Successive fractions containing 92.1~97.8% of EPA were collected. The average concentration of three purified fractions was 95.6% with the recovery rate of 30%.

• Nuclear Engineering and Technology
• /
• v.25 no.2
• /
• pp.259-264
• /
• 1993

Ion chromatographic method has been applied for burnup measurement of irradiated nuclear fuel by dynamic system using 1-octanesulfonate as a cation exchanger and $\alpha$-hydroxyisobutyric acid as an eluant. A number of elution techniques were evaluated for the optimum separation of plutonium, uranium and neodymium. These elements were individually separated and collected by gradient elution between 0.05 M and 0.40 M of $\alpha$-hydroxyisobutyric acid in a single column, and finally determined by isotope dilution mass spectrometry. The burnup data from this method were compared with those from conventional anion exchange method. The results showed a good agreement within 3.5 % of difference between two methods.

• KSBB Journal
• /
• v.16 no.6
• /
• pp.533-537
• /
• 2001

${\alpha}$-lactalbumin and ${\beta}$-lactoglobulin in whey proteins were separated by high performance membrane chromatography (HPMC). The separation mechanism involved anion-exchange, and the stationary phase was anion CIM (Convective Interaction Media) DEAE, QA disk and cation exchanger SO$_3$(16${\times}$3 mm). Two types of mobile phase were used, buffer A (20 mM Tris-HCI, pH 7.3) and buffer B(buffer A + 1 M NaCl), As the amount of NaCl dissolved in buffer linearly increased, which enabled a gradient elution mode. The optimum mobile phase and operating condition (Buffer A/Buffer B = 100/0 - 30/70 vol%, gradient time 1 min, 30/70 - 10/90 vol.%, gradient time 2 min) were experimentally determined. In this experimental condition, ${\alpha}$-lacta1bumin, ${\beta}$-lactoglobulin were separated within 5 min at a mobile phase flow rate of 4 mL/min.