• 분석과학
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• 제15권3호
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• pp.190-195
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• 2002

본 연구에서는 ion-pair reversed-phase high performance liquid chromatography (IP-RP-HPLC)방식을 이용한 denaturing high performance liquid chromatography (DHPLC)방법을 사용하여 기관지 천식을 조절하는 ${\beta}_2$-교감신경수용체 유전자의 돌연변이를 검출하였다. 50명의 천식 환자의 혈액에서 genomic DNA를 추출하여 중합효소연쇄반응 (polymerase chain reaction, PCR)을 이용해 증폭하고, 그 산물을 DHPLC로 분석한 결과, 50개의 시료 가운데 15개 (30%)의 돌연변이를 검출하였다. 최종적으로 유전자 염기서열결정법을 통해 DHPLC의 돌연변이 검출률이 정확함을 확인하였다.

• 분석과학
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• 제7권2호
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• pp.165-171
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• 1994

화학 발암제인 dimetylnitrosamine(DMN)을 Hamster에 구강투여하였을 때 간의 아미노산 조성에 미치는 영향을 규명하기 위하여 reversed phase liquid chromatography법으로 아미노산을 정량하였다. DMN을 투여한 실험군의 간에서의 아미노산의 농도는 대조군에 비해 aspartic acid, glycine, glutamine, histidine, proline, tyrosine, leucine 등은 약 2배, valine, tryptophan은 약 3배, phenylalanine은 약 10배 증가하였고, threonine은 23%로 감소하였으며, serine, alanine, arginine, methionine, isoleucine, lysine은 큰 변화가 없었다.

• 분석과학
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• 제11권5호
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• pp.404-408
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• 1998

Using a reversed-phase high performance liquid chromatography, the separation of 20(S)-, 20(R)-prosapogenin stereo-isomers of ginsenoside-$Rg_2$ and of ginsenoside-$Rg_3$ in ginseng saponins has been carried out with binary solvent system. The optimum conditions for the isomer separation are as following: Nova-$Pak^{(R)}C_{18}$ (Waters, $3.9{\times}150mm$) column, $CH_3CN/CH_3CN$ (100:8, v/v) binary solvent system and the flow rate was 1.7 mL/min. The stereoisomers were separated with change of the mixture ratio of the solvent system, the solvent elution by gradient program, and then detected at 203 nm of UV detector. The simultaneous separation of mixture that were the $Rg_2$, $Rg_3$ isomers was easily performed in nonpolar solvent for $Rg_2$, polar solvent for $Rg_3$ at the same optimum conditions.

• Bulletin of the Korean Chemical Society
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• 제14권4호
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• pp.510-514
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• 1993

The retention behavior of proteins was investigated by using reversed-phase chromatography (RPC), comparing to the retention behavior of small molecules in RPC. The evaluation was carried out on a SynChropak RP-P($C_{18}$) column with 0.1% aq. TFA-organic solvent modifier such as acetonitrile, isopropanol, and ethanol. The Z value (the number of solvent molecules required to displace the solute from the surface) was a general index for the characterization of protein retention as a function of organic concentration over a range of temperature between 5 and 70$^{\circ}C$. Van't Hoff plots provided the basis for evaluating the enthalpic and entropic changes associated with the interaction between protein and the stationary phase. Z values did not change significantly at the range of temperature showing the consistent ${\Delta}H^{\circ}$ and ${\Delta}S^{\circ}$ values. From these investigation, it was concluded that the retention behavior of proteins in RPC was able to be predicted by the retention parameters applied to small molecules. Furthermore, myoglobin and hemoglobin in RPC as stated above showed a similar retention behavior regardless of their molecular weights.

• Bulletin of the Korean Chemical Society
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• 제24권12호
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• pp.1781-1784
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• 2003

Determination of Co(II) ion as a 4-(2-thiazolylazo)resorcinol(TAR) or 5-methyl-4-(2-thiazolylazo)resorcinol(5MTAR) chelate was accomplished by reversed-phase capillary high-performance liquid chromatography (RP-Capillary-HPLC) using a Vydac $C_4$ column and MeCN-water mixture as mobile phase. The effect of change in pH and MeCN percentage of the mobile phase on the retention factor, k and peak intensity were evaluated. It was found that 30% MeCN (v/v) of pH 5.60 or 7.20 was adequate as mobile phase when TAR or 5MTAR is used. Detection limit (D.L., S/N=3) in each case was $2.0\;{\times}\;10^{-7}$M (11.8 ppb) and $3.0\;{\times}\;10^{-7}$ M (17.7 ppb). The Co(II) ion in mineral and waste water was determined with the optimum column and mobile phase.

• Archives of Pharmacal Research
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• 제22권6호
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• pp.614-618
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• 1999

A reversed-phase high-performace liquid chromatographic method was developed to determine the optical purity of metoprolol enantiomers. The enantiomers were converted to diastereomeric derivatives using (-)-menthyl chloroformate reagent. Separation of the enantiomers as diastereomers was achieved by reversed-phase HPLC within 30 min using Inertsil C8 column. This method allowed determination of 0.05% of either enantiomer in the presence of its stereoisomer and method validation showed adequate linearity over the required range. Owing to the reaction condition during the derivatization with (-)-menthyl chloroformate, the possibility of racemization had to be established. Different ratios of (S)-(-)-metoprolol and (R)-(+)-metoprolol were prepared. Enantiomeric separation of these mixtures took place on a chiralcel OD column or, after derivatization with (-)-menthyl chloroformate, on a C8 column. The results form the these two independent separation systems were compared with trace racemization and were in very good agreement. No racemization was found during the experiment.

• 대한본초학회지
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• 제23권4호
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• pp.171-177
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• 2008

Objectives: This study presents a reversed-phase high-performance liquid chromatography- pulsed amperometric detection(RP-HPLC-PAD) method for the determination of puerarin and daidzin in Puerariae Radix extract and Chinese medicinal preparations. Methods: Chromatographic separation was performed using a 10% acetonitrile with a reversed-phase column(Unison UK-C18, $100mm{\times}2.0mm$ I.D.; $3{\mu}m$). The analyses were detected by pulsed amperometric detector(PAD) in alkaline conditions by combining with post-column NaOH solution. Geniposide was used as an internal standard. Results: The limit of detection(S/N=3) and the limit of quantification(S/N=10) were 0.025 ng, 0.075 ng for puerarin, and 0.05 ng, 0.15 ng for daidzin, respectively. The intra- and inter-day precisions(RSDs) were less than 6.5% and average recoveries of puerarin were 99.7-101.3% and those of daidzin were 101.0-102.8%. Conclusions: According to above results, we developed a determination method for puerarin and daidzin in Puerariae Radix with high sensitivity and selectivitely.

• 대한화학회지
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• 제38권7호
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• pp.502-508
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• 1994

염의 농도가 큰 시료용액중에 미량으로 함유되어 있는 U(VI)과 Th(VI)을 액상크로마토그래피로 동시에 분리, 정량하였다. 약 2ml의 시료를 pH5.5의 0.11M ${\alpha}$-HIBA 용리액과 함께 C_{18}$ 역상농축컬럼에 통과시켜 U(VI)과 Th(VI)을 농축시켰으며, 농축된 이들 원소들을 다시 비활성 C_{18}$ 역상분리컬럼에서 pH3.0의 0.17M ${\alpha}$-HIBA/0.0038 M 1-pentanesulfonate 용리액으로 각각 분리하였다. 분리된 이들 원소들은 Arsenazo III를 사용하는 postcolumn반응으로 검출되었으며, 검출한계는 두 원서 모두 1ppb이었다.

• 한국산업보건학회지
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• 제4권2호
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• pp.189-197
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• 1994

Analytic methods for Cr(VI) level in industrial hygienic field were suggested by the National Institute for Occupational Safety and Health(NIOSH method 7600, 7604). There were growing needs for measurement of Cr(III) and Cr(VI) levels simultaneously. Two analytical methods were suggested to determine Cr(III) and Cr(VI) levels simultaneously. The one is method by using reversed phase high peformance liquid chromatography(HPLC) and the other is by using ion exchange HPLC. The purpose of this work was to evaluate the usefulness of these two analytic methods. For the difference of ionic charges of Cr(III)-ethylendiamine tetraacetic acid(EDTA) chelate and $CrO_4{^-2}$, we could detect them simultaneously by ion exchange HPLC. Also, we attempted to determine the levels of Cr(III) and Cr(VI) chelated with sodium diethyldithiocarbamate(NaDDTC) by using reversed phase HPLC. The confirmation of Cr(III) and Cr(VI) were checked by fraction collector and nameless atomic absorption spectrometer. The optimal conditions for the formation of Cr(III)-EDTA chelate were two hours incubation period with pH 5. Cr(III)-EDTA and Cr(VI) in EDTA solution were successfully separated by anion exchange column using $Na_2CO_3/NaOH$ mixture as mobile phase. Peaks of Cr(III)-EDTA and Cr(VI) in EDTA were identified at 5 minutes and 7 minutes of retention time respectively by the ion exchange HPLC. The formation of Cr(III)-NaDDTC and Cr(VI)-NaDDTC chelates were twelve hours incubation period. Cr(III)-NaDDTC and Cr(VI)-NaDDTC chelates were separated by reversed phase column using methanol and water mixture as mobile phase. Peaks of Cr(VI)NaDDTC and Cr(III)-NaDDTC chelates were identified at 13 minutes and 26 minutes of retention time respectively by the reversed phase HPLC. Due to reduction of Cr(VI) to Cr(III), it seems to be not suitable for simultaneous determination of Cr(III)-NaDDTC and Cr(VI)-NaDDTC chelates by reversed phase HPLS. Simultaneos determination of Cr(III) and Cr(VI) by ion exchange HPLC was more accurate and simple method.

• Bulletin of the Korean Chemical Society
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• 제28권4호
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• pp.601-606
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• 2007

The chromatographic behaviors of nucleotides (inosine 5'-monophosphate, uridine 5'-monophosphate, guanosine 5'-monophosphate, and thymine monophosphate disodium salts) on a C18 column were studied with different types of ionic liquids (ILs) as additives for the mobile phase in reversed-phase liquid chromatography (RPLC). Three ILs, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]), 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIm][BF4]), and 1-ethyl-3-methylimidazolium methylsulfate ([EMIm][MS]), were used. Eluents were composed of water and methanol (90/10%, vol) with the addition of 0.5-13.0 mM of ILs. The effects of the concentration of ILs on retention and separation were investigated and discussed. The results showed that the addition of ILs affects the retention and resolution of the tested compounds. Use of 13.0 mM of [BMIm][BF4] as the eluent modifier resulted in a baseline separation of nucleotides without requiring gradient elution. This study demonstrates that ILs can be potentially applied as a mobile phase modifier in RPLC.