Browsing by Author "Kuo, KL"

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Analysis of prostaglandins by micellar electrokinetic capillary chromatography
(1997-02-14)
Hsieh, YZ
;
Kuo, KL
;
應用化學系
;
Department of Applied Chemistry
This paper presents a rapid and reliable micellar electrokinetic capillary chromatography (MEKC) method to separate major prostaglandins and thromboxane B-2. The running buffer was modified with sodium dodecyl sulfate (SDS). The effects of the SDS concentration on the migration behavior of analytes was also examined. Moreover, the influences of electrolyte concentration and capillary temperature on the separation were investigated. In optimum conditions, seven major prostaglandins and thromboxane B-2 could be separated within 8 min. The relative standard deviations of the migration times (reproducibility) of the analytes were less than 0.82%.
Analysis of prostaglandins by micellar electrokinetic capillary chromatography
(1997-02-14)
Hsieh, YZ
;
Kuo, KL
;
交大名義發表
;
應用化學系
;
National Chiao Tung University
This paper presents a rapid and reliable micellar electrokinetic capillary chromatography (MEKC) method to separate major prostaglandins and thromboxane B-2. The running buffer was modified with sodium dodecyl sulfate (SDS). The effects of the SDS concentration on the migration behavior of analytes was also examined. Moreover, the influences of electrolyte concentration and capillary temperature on the separation were investigated. In optimum conditions, seven major prostaglandins and thromboxane B-2 could be separated within 8 min. The relative standard deviations of the migration times (reproducibility) of the analytes were less than 0.82%.
Analysis of Puerariae radix and its medicinal preparations by capillary electrophoresis
(1998-04-03)
Wang, CY
;
Huang, HY
;
Kuo, KL
;
Hsieh, YZ
;
應用化學系
This study presents a high-performance capillary electrophoresis (CE) method to analyze five constituents of Puerariae radix, an important crude herb used in Chinese medicine. Puerarin, daidzin, daidzein, genistein and biochanin A are the bioactive constituents of Puerariae radix. Herein, those analytes were successfully separated within 6 min using a pH 10.1 borax-NaOH buffer. The effects of pH value and concentration of the running buffer on the separation of the fie analytes were also examined. The relative standard deviations of the analytes' migration times were less than 0.38% under the optimized separation conditions. Notably, the correlation coefficients of the analytes' linear calibration graphs exceeded 0.998. Moreover, the amounts of the five constituents in three different Puerariae radix samples were determined by the CE method with a relatively simple extraction procedure. (C) 1998 Elsevier Science B.V.
Determination of cinnamaldehyde, cinnamic acid, paeoniflorin, glycyrrhizin and [6]-gingerol in the traditional Chinese medicinal preparation Kuei-chih-tang by cyclodextrin-modified micellar electrokinetic chromatography
(1997-05-30)
Huang, HY
;
Kuo, KL
;
Hsieh, YZ
;
應用化學系
;
Department of Applied Chemistry
This study presents a cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) technique with a multi-wavelength detection method to determine specific components in Kuei-chih-tang. Kuei-chih-tang, a Chinese medicinal preparation, is composed of five crude herbs, i.e., Cinnamomi ramulus, Paeoniae radix, Glycyrrhizae radix, Zingiberis rhizoma and Zizyphi fructus. The effects of SDS and gamma-cyclodextrin on the analytes' migration behavior were examined. The selected components were successfully separated within 10 min using a pH 10.0 borax-NaOH buffer containing 20 mM SDS and 2 mM gamma-cyclodextrin. The correlation coefficients of the linear calibration graphs for the analytes exceeded 0.993. Moreover, the optimized CD-MEKC method was employed to analyze four different Kuei-chih-tang samples. (C) 1997 Elsevier Science B.V.
Determination of preservatives in food products by cyclodextrin-modified capillary electrophoresis with multiwavelength detection
(1997-04-25)
Kuo, KL
;
Hsieh, YZ
;
應用化學系
;
Department of Applied Chemistry
A high-performance capillary electrophoretic method with multiwavelength detection was developed to analyze frequently used preservatives. The effects of alpha-cyclodextrin and beta-cyclodextrin on migration behaviours of nine preservatives were investigated. The preservatives were successfully separated within 9 min using a borax-NaOH buffer (pH 10.0) modified with 2 mM alpha-cyclodextrin. In optimized separation conditions, the reproducibilities of the migration times of the preservatives were satisfactory (R.S.D. values <0.99%). The correlation coefficients of the linear calibration graphs for the preservatives, ranging between 5 and 500 mu g ml(-1), exceeded 0.991. By employing this reliable capillary electrophoresis method, preservatives in three different food products were determined.
High-performance capillary electrophoretic analysis of synthetic food colorants
(1998-03-01)
Kuo, KL
;
Huang, HY
;
Hsieh, YZ
;
應用化學系
;
Department of Applied Chemistry
A high-performance capillary electrophoresis method with diode-array detection has been developed for analysis of synthetic food colorants. The influence of buffer composition on the separation of the food colorants was examined, as were the effects of alpha-, beta- and gamma-cyclodextrins on analyte migration behavior. Eight food colorants were completely separated within 10 min using pH 9.5 borax - NaOH buffer containing 5 mM beta-cyclodextrin. Experimental results indicate that the relative standard deviations of analyte migration times were < 0.88% under the optimized separation condition. Correlation coefficients of the linear calibration plots of the analytes exceeded 0.998. The method was suitable for determination of the quantities of synthetic food colorants in ice cream bars and fruit soda drinks.
Separation of retinoids by micellar electrokinetic capillary chromatography
(1997-02-14)
Hsieh, YZ
;
Kuo, KL
;
交大名義發表
;
應用化學系
;
National Chiao Tung University
In this study, we have developed a micellar electrokinetic capillary chromatography (MEKC) method with diode-array detection to separate five important retinoids, including retinol, retinal, retinoic acid, retinyl acetate and retinyl palmitate. These very hydrophobic retinoids are successfully separated with phosphate buffer containing sodium deoxycholate (SDC) and Brij 35 as the micellar pseudostationary phase. The effects of SDC and Brij 35 concentration on the migration behavior of the five retinoids are also discussed. The relative standard deviations of the migration times of the retinoids are less than 1.9% in the optimized separation condition. Moreover, a direct extraction method without saponification is employed to extract retinyl esters in pharmaceutical products. The ranges of recoveries are 95%-99% for retinyl esters with less than 2% relative standard deviations. Therefore, retinyl esters in pharmaceutical products can be determined by combining the direct extraction and the MEKC methods.