• Analytical Science and Technology
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• v.12 no.4
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• pp.341-345
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• 1999

The separation and determination of inorganic cations by a capillary zone electrophoresis was studied. Cations were separated by the capillary column and detected by indirect UV method. The running buffer of 0.03 M creatinine and 0.02 M-hydroxy isobutylic acid solution (pH 4.8) was used to improve the mobility of ions in the column. A potential of 18 kV was applied at anode. A complete separation of cations ranged within 15 min and detection limits were between 0.1 and 1.0 ppm. The applicability of the method for real samples was demonstrated.

• Analytical Science and Technology
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• v.11 no.3
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• pp.213-221
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• 1998

The determination of inorganic anions by capillary zone electrophoresis is reported. A ten component synthetic mixture of anions of bromide, chloride, fluoride, nitrite, nitrate, sulfite, sulfate, perchlorate, chlorate and chlorite was separated by the capillary column and detected by indirect UV method. The running buffer contained 5 mM ammonium dichromate, 10 mM ammonium acetate, 20 mM diethylenetriamine, 10% methanol solution at pH 9.3. A potential of 15 kV at the cathode (reversed polarity) was utilized for the separation of inorganic anions. A complete separation of anions was achieved in less then 10 min and the applicabilities of the method for the analysis of real samples was demonstrated. We compare the concentration of anions in toluene inhaled humen's urine and in postmortem bloods obtained by capillary zone electrophoresis and ion chromatograph.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.230.3-231
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• 2003

The therapeutic use of protein pharmaceuticals produced by recombinant DNA technology is increasing in recent decades. In order to investigate the quality of recombinant proteins, it is important to identify and assign the impurities produced in the process of recombination or in storage conditions. Capillary Electrophoresis is emerging technology exhibiting high sensitivity, selectivity and speed and may be most powerful tools for this application. In this study, human growth hormone (hGH) has been analyzed by various mode of capillary electrophoresis such as capillary zone electrophoresis (CZE), capillary gel electrophoresis (CGE), and capillary isoelectric focusing (cIEF) to indicate the chemically or biologically oriented variants and the degraded fragments. (omitted)

• YAKHAK HOEJI
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• v.41 no.5
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• pp.539-546
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• 1997

Capillary electrophoresis (CE) is perceived as an attractive tool for the analysis of pharmaceuticals and biological materials because of their high separation efficiency, easy separation and low running cost. New concept of micellar electrokinetic capillary chromatography (MECC) expanded the application of CE to the separation of neutral molecules. Validation of CE as an analytical technique for quality control of pharmaceuticals should be confirmed by quantitative analysis and the peak confirmation. In this study, the quantitative analyses of various types of neutral, acidic and basic components (acetaminophen, caffeine, ascorbic acid, riboflavin, thiamine, chlorpheniramine, phenylpropanolamine, dl-methylephedrine and dextromethorphan) in complex cold medicines have been accomplished using CE. Combined methods of MECC using SDS and capillary zone electrophoresis lowering the pH of running buffer were adopted to determine the ingredients in capsule type or liquid formula complex medicines without particular sample pretreatment. The results indicate that CE is a promising technique for quality control analysis of pharmaceuticals as a validation method.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4316-4320
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• 2011

The effects of various hydroxide compounds on base stacking (BS) were investigated for pre-concentration of DNA molecules in capillary electrophoresis (CE). In BS, hydroxide ions ($OH^-$) were electrokinetically introduced after DNA sample injection. A neutralization reaction occurred between the $OH^-$ and $Tris^+$ of the running buffer, which resulted in a zone of lower conductivity. Within the low conductivity zone of the high electric field, the DNA molecules moved more rapidly and were concentrated in front of the low conductivity zone. At the same BS conditions of CE, the enhanced sensitivity of the DNA samples was dependent on the kind of multivalent cations in the hydroxide compounds. Except for LiOH, the hydroxide compounds with monovalent cations showed more effective BS than those with divalent cations because of solubility, ionic strength and electronegativity. The order of hydroxide compounds that enhance the detection sensitivity of DNA molecules was as follows: NaOH > $NH_4OH$ > KOH > $Ba(OH)_2$ > $Sr(OH)_2$ > LiOH > $Ca(OH)_2$ > $Mg(OH)_2$. $NH_4OH$, KOH and $Ba(OH)_2$ proved to be efficient hydroxide compounds to use as effective BS reagents in CE instead of NaOH.

• Analytical Science and Technology
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• v.8 no.4
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• pp.881-886
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• 1995

Several forms of gangliosides have been separated from various types of biological matrices using cyclodextrin-modified capillary zone electrophoresis (CZE). Quantitative analysis of phospholipids from biological fluids was achieved by micellar electrokinetic capillary chromatography (MECC) using 35mM sodium dodecyl sulfate. Phosphorylation, one of the most important post-translational modifications of proteins at serine, threonine and tyrosine residues in small peptides were identified and quantitative analyses of phosphopeptides were performed. Seven different neuropeptides which are relative the pain reachanism in the vertebrate central nervons system were also separated by CZE.

• Journal of the Korean Chemical Society
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• v.35 no.3
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• pp.219-225
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• 1991

Capillary zone electrophoresis (CZE) which is highly efficient separation technique has been domestically established having optimum detection sensitivity. By applying 20∼35 kV of electric potential to the narrow (50 ${\mu}m$ i.d.) capillary tubing filled with running buffer, this technique can quickly (< 20 min) separate the small quantities of sample with high separation efficiency (number of theoretical plates : 200,000∼500,000). Factors affecting the separation efficiency and resolution in CZE were examined by analyzing adenine and catecholamine derivatives.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1496-1500
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• 2010

Sibutramine enantiomers were separated successfully by capillary zone electrophoresis using substituted cyclodextrins as chiral selectors. The effects of cyclodextrin concentration, pH, voltage, buffer type, and electrolyte concentration on the migration time and resolution of enantiomers were examined. Separation of sibutramine enantiomers on an unmodified fused silica capillary (total length, 54 cm; effective length, 45 cm) was achieved using a mixed buffer of 20 mM phosphate/10 mM citrate containing either 5 mM methyl-${\beta}$-cyclodextrin (pH 4.3) or 5 mM carboxymethyl-${\beta}$-cyclodextrin (pH 6.5). Samples were injected with a pressure of 50 mbar for 5 s and were detected at a wavelength of 223 nm. The established method showed good precision and accuracy, with intra- and inter-day variations of less than 2.9 and 4.7%, respectively, and recoveries of 95.7 - 103.8%. The stability constants of (R)- and (S)-sibutramine demonstrated that the resolution of sibutramine enantiomers was attributable primarily to the difference in stability constants. When this optimized method was applied to the determination of sibutramine enantiomers in commercial drug formulations, it proved to be economical and convenient, affording sufficient accuracy, precision, and reproducibility as well as sensitivity and selectivity.

• Bulletin of the Korean Chemical Society
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• v.25 no.3
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• pp.377-381
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• 2004

Chiral separation of aryalcohols such as 1-phenyl-propanol, 1-phenyl-2-proanol, and 2-phenyl-1-propanol by capillary electrophoresis has been optimized using the overlapping resolution mapping (ORM) scheme. Three critical parameters of the electrophoretic media, i.e. phosphate concentration, sulfated ${\beta}$-cyclodextrin (CD) concentration and pH, were chosen for optimization. The working ranges were initially presumed by 7 preexperiments. Further optimization was carried out by another seven experiments within the narrow working ranges. From the final overlapping resolution mapping all peak pairs, the area of maximum separations were located. Using the conditions of a point in this area, we found that the target compounds were a baseline separated within 30 min. The maximum separation conditions of arylalcohols were a chiral selector concentration of 5.4%, a phosphate concentration of 28 mM, and a pH of 5.0.

• KSBB Journal
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• v.18 no.4
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• pp.255-260
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• 2003

In vivo bioassays for biological medicines have been considered final resort to unequivocally assess the biological activities for them because there are some cases in which the biological activities obtained from in vivo bioassay and in vitro bioassay quite differ each other. The in vivo biological activity of EPO depends on its sialic acid contents which confer microheterogeneity-isoforms to this protein. We have devise a method which consists of a in vitro bioassay using BaF3 cell line and a capillary zone electrophoresis (CZE) for the measurement of the EPO isoform distribution. The biological activity of EPO obtained using in vitro bioassay with BaF3 cell line showed good correlation (C.V.(％) 7.34, 5.85, 8,16, 8.08, 8.8) to EPO content measured either spectrophotometric assay (A280 0.1 ％ ＝0.743) or radio immunoassay. The assay validation results of in vitro bioassay with 3 lot of in house EPO showed good results to EPO content measured either in vivo assay or radio immunoassay. and also showed good results the robustness of our method in terms of precision, accuracy, repeatability. The isoform distribution for EPO-BRP (1 : 1 mixture of epoetin-${\alpha}$ and epoetin-${\beta}$, European Pharmacopoeia) by CZE method resulted in isoform 2 through isoform 8. The major peaks in electrophoregram were composed of isoform 3 through 7. Our recombinant EPO (epoetin-${\alpha}$) having equivalent in vivo biological activity showed the isoform distribution of isoform 3 through 9. The major peaks consisted of isoform 4 through 8. The peak area of isoform 4 was always smaller than that of isoform 5. The preparations of recombinant epoetin-${\alpha}$ with lower in vivo biological activity than EPO-BRP showed the isoform 2 through 8 in their electrophoregrams whose major peaks consisted of the isoform 3 through 7. The peak area of isoform 4 was larger than that of isoform 5.