• Analytical Science and Technology
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• v.15 no.3
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• pp.190-195
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• 2002

We analysed mutation of ${\beta}_2$-adrenergic receptor gene that controls bronchial asthma by denaturing high performance liquid chromatography (DHPLC) according to ion-pair reversed-phase high performance liquid chromatography (IP-RP-HPLC). We extracted genomic DNA from 50 asthma patients, amplified DNA using PCR, and analysed PCR product by DHPLC. As a result, we obtained that mutation frequency was 15 (30%) among 50 cases. Consequently DHPLC mutation detection was confirmed that the result of direct sequencing was coincide exactly.

• Bulletin of the Korean Chemical Society
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• v.33 no.12
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• pp.3971-3976
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• 2012

A simple method was developed for the analysis of seven stilbene-type fluorescent whitening agents (FWAs) in paper materials by ion-pair reversed-phase high-performance liquid chromatography with fluorescence detection. These stilbene-type FWAs included two disulfonate, two tetrasulfonate, and three hexasulfonate compounds. After optimization of chromatographic conditions, the FWAs were satisfactorily separated using a reversed-phase column (RP-18) with the following isocratic mobile phase: methanol-water (60:40) containing 17.5 mM TBABr and 10 mM citrate buffer (pH = 7.0). The calibration plot was linear in the range from 5 to 500 ng/mL for two disulfo-FWAs and from 1 to 500 ng/mL for the other five FWAs. Precision levels of the calibration curve as indicated by RSD of response factors were 1.2 and 8.1%. Limits of quantitation (LOQ) ranged from 1.2 to 11 ng/mL.

• KSBB Journal
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• v.25 no.5
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• pp.459-465
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• 2010

A simple and efficient analytical method for the simultaneous determination of seven tar color additives was developed using ion pair high performance liquid chromatography. The conditions for HPLC analysis were as follows: column, ${\mu}$-Bondapak C18 (10 ${\mu}m$, 300 ${\times}$ 3.9 mm i.d.); gradient mobile phase, 0.025 mol/L ammonium acetate (containing 0.01 mol/L tetrabutylammonium bromide)-acetonitrile-methanol (65:25:10) as a mobile for fraction A and 0.025 mol/L ammonium acetate (containing 0.01 mol/L tetrabutylammonium bromide)-acetonitrilemethanol (40:50:10) as a mobile for fraction B; flow rate, 1.0 mL/ min; detection wavelength, 254/520/620 nm. We could attain to the detection limits as 0.01~0.05 ${\mu}$g/mL (254 nm) and 0.005~0.01 ${\mu}$g/mL (520 nm) for six red tar color additives, and 0.05 ${\mu}$g/mL (254 nm) and 0.002 ${\mu}$g/mL (620 nm) for Fast green FCF. This analytical method was applicable to determine the tar color additives contained in several commercial cold syrups.

• Archives of Pharmacal Research
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• v.19 no.5
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• pp.396-399
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• 1996

High-performance liquid chromatographic method with UV detecction was developed for the determination of theophylline and its metabolites in human urine using ${beta}$-hydroxyethyl theophylline$({beta} -HET)$ as an internal standard. For extraction of urine sample, quality control sample and xanthine-free blank urine were mixed with decylamine (ion-paring reagent) and ${beta}$-HET. After saturation with ammonium sulfate, the mixture was then extracted with organic solvent at pH values of 4.0-4.5. All separations were performed with ion-pair chromatography using decylamine as an ion-pairing reagent and 3mM sodium acetate buffered mobile phase (pH 4.0) containing 1% (v/v) acetonitrile and 0.75 mM decylamine. The detection limits of theophylline, 1, 3-DMU, 1-MU, 3-MX and 1-MX in human urine were 0.17, 0.17, 0.39, 0.19 and 0.19 ${\mu}g$/ml, based on a signal-to-noise ratios of 3.0. The mean intraday coefficients of variation (C.V.s) of each compound on nine replicates were lower than 2.0%, while mean interday C.V.s on three days were lower than 1.6%. All separations were finished within 40miutes.

• Analytical Science and Technology
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• v.17 no.1
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• pp.53-59
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• 2004

Up to now, methods for the detection of genetic alterations as single strand conformation polymorphism (SSCP) or denaturing gradient gel electrophoresis (DGGE) have been used. It is too labor-intensive and expensive to serve for routine analysis. Moreover, lower in its sensitivity and specificity being also strongly dependent on the experience of the investigater. To improve these problems, we analysed mutation of ${\beta}_2$-adrenergic receptor gene that controls bronchial asthma by denaturing high performance liquid chromatography (DHPLC) according to ion-pair reversed phase chromatography (IP-RPC). We extracted genomic DNA from 80 asthma patients and then amplified DNA using PCR and analysed PCR product by SSCP and DHPLC. As a result, we analysed mutation frequency is 19 (23.75%) on SSCP and 25 (31.25%) on DHPLC in ${\beta}_2$-adrenergic receptor gene. We conclude that DHPLC is a fast and simple screening method rather than SSCP analysis.

• Analytical Science and Technology
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• v.12 no.3
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• pp.203-208
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• 1999

The ion-pair high performance liquid chromatographic elution behavior of salicylic acid and its derivatives was studied with measuring capacity factor, k', changing the concentration of ion-pairing reagent (tetrabutylammonium chloride, TBACl) in mobile phase. As a result, it was found that k' of the samples increase at pH 7.2 as the TBACl concentration increases. The derivatives of salicylic acid were separated each other at an optimum mobile phase condition which was found from the observation of the retention behavior. The optimum mobile phase condition was methanol solution($MeOH:H_2O_2$ 30:70) containing 20 mM TBACl for the determination of salicylic acid and methanol solution($MeOH:H_2O_2$ 20:80) containing 40 mM TBACl for p-aminosalicylic acid at pH 7.2. The method has been applied for the analysis of the contents of salicylic acid derivatives in an aspirin tablet and a tuberculosis curing agent.

• Analytical Science and Technology
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• v.10 no.4
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• pp.231-239
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• 1997

We developed a procedure that can effectively separate and determine tertiary amines and quaternary ammonium salts in some samples with reverse phase ion-pair high performance chromatography, employing indirect spectrophotometric detection method. Detection and ion-pairing reagents used in this study were benzyl trimethylammonium chloride (BTMACl) and sodium dodecyl sulfate(DDSANa), respectively. Eluting the electrolyte solutions of some commercial electrolytic capacitors with a MeOH(40):water(60) eluent (pH 8.5 adjusted with NH4Cl-NH3 buffer) containing 0.010M DDSANa and 0.004 M BTMACl through Supelco LC-18 or ${\mu}$-Bondapak phenyl column, amines and ammonium salts contained in the sample were successfully separated and determined. Varying the composition, especially the content of quaternary ammonium salts, of electrolyte solutions based on this analysis. we could prepare the low impedance(0.08~0.13) electrolytic capacitors with excellent electrical properties and it was a confirmation that the analysis is favorable.

• YAKHAK HOEJI
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• v.44 no.2
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• pp.135-140
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• 2000

Determination of Aconitum alkaloids in processed Buza (Cho-0, Salted Buza, Moist-heating Buza, Limed Buza), which had been prepared from the raw tubers of Aconitum chiisanenseb(Ranunculaceae), was established using visible spectrophotometry and high-performance liquid chromatography (HPLC) method especially for Aconitine analysis. Aconitum alkloids were reacted with tetra- thiocy-anatocobalt[II] complex ion to form a stable ion pair. The reaction product was insoluble in water but freely soluble in several organic solvents. 1.2-Dichloroethane was the best extracting solvent among the examined solvents. Spectrophotometry of Aconitum alkaloids at nax. 625 was carried out. The HPLC method for aconitine was carried out using Radial PAK-CN column with gradient solvent system by solvent mixture of acetonitrile and phosphate buffer (pH 3.0) at 4$0^{\circ}C$ and 254 nm. Linear relationship was found between absorbance response and concentration of aconitine in range of 0.45 mM~0.9 mM ($r^2$=0.9949) by spectrophotometry and 0.3 mM~1.2mM($r^2$=0.9983) by HPLC method. These methods have been found to be suitable and reproducible for routine analysis of Aconitum alkaloids and its pharmaceutical preparations.

• The Korean Journal of Food And Nutrition
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• v.24 no.3
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• pp.414-421
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• 2011

시중에 유통 중인 영양보충용 제품의 수용성 비타민 $B_1$(thiamin), $B_2$(riboflavin), $B_3$(nicotinic acid and nicotine amide), $B_6$(pyridoxine), C(ascorbic acid)의 신속한 동시분석 방법을 확립하기 위하여 본 연구를 실시하였다. 영양보충용 제품은 정제, 연질캅셀, 분말, 액상의 4가지 제형에 대해 27종의 제품을 구입한 후, Ion-pair 분리기법을 사용하여 HPLC-UVD를 이용한 동시분석 방법을 검토하였다. 비타민 $B_1$, $B_2$, $B_3$, $B_6$, C의 HPLC에 의한 동시분석 조건을 검토한 결과, 이동상은 0.02% triethylamine, 17.5% 메탄올, $5{\mu}M$ sodium hexanesulfonic acid가 함유된 pH 3.5(acetic acid로 조절)의 수용액을 사용하였고, 용출시간은 다른 피크의 영향을 받지 않도록 30분으로 하였다. 수용성 비타민의 회수율은 96% 이상이었다. 본 연구에 의해 확립된 수용성 비타민의 동시분석 조건은 검량선의 직선성, 정밀성, 정확성, 기기적합성 등이 USP 및 ICH 기준에 적합하여 HPLC의 동시분석 방법으로 합당하였다. 수용성 비타민의 추출 용매는 제형에 따라 약간의 차이를 보이긴 했으나, 물이나 산성조건을 갖춘 HPLC의 이동상이 에탄올이나 메탄올보다 높은 추출 효율을 보였다. 초음파 추출기에 의한 추출 시간은 20분이 가장 적당하였다. 본 연구의 결과는 수용성 비타민의 신속한 추출 및 분석에 매우 효율적으로 이용될 것으로 기대된다.

• Journal of Ginseng Research
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• v.42 no.1
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• pp.21-26
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• 2018

Background: Furosine (${\varepsilon}$-N-2-furoylmethyl-L-lysine, FML) is an amino acid derivative, which is considered to be an important indicator of the extent of damage (deteriorating the quality of amino acid and proteins due to a blockage of lysine and a decrease in the digestibility of proteins) during the early stages of the Maillard reaction. In addition, FML has been proven to be harmful because it is closely related to a variety of diseases such as diabetes. The qualitative analysis of FML in fresh and processed ginsengs was confirmed using HPLC-MS. Methods: An ion-pair reversed-phase LC method was used for the quantitative analysis of FML in various ginseng samples. Results: The contents of FML in the ginseng samples were 3.35-42.28 g/kg protein. The lowest value was observed in the freshly collected ginseng samples, and the highest value was found in the black ginseng concentrate. Heat treatment and honey addition significantly increased the FML content from 3.35 g/kg protein to 42.28 g/kg protein. Conclusion: These results indicate that FML is a promising indicator to estimate the heat treatment degree and honey addition level during the manufacture of ginseng products. The FML content is also an important parameter to identity the quality of ginseng products. In addition, the generation and regulation of potentially harmful Maillard reaction products-FML in ginseng processing was also investigated, providing a solid theoretical foundation and valuable reference for safe ginseng processing.