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Volume 46, Issue 6
Displaying 1-17 of 17 articles from this issue
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Takao TSUDA, Shinya KITAGAWA, Rajeev DADOO, Richard N. ZARE1997 Volume 46 Issue 6 Pages 409-414
Published: June 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe flow profile of electroosmosis in capillary-zone electrophoresis was observed using a microscope-CCD-video system, rectangular capillary (50×1000 μm) and fused-silica capillary (75 μm in diameter). A rhodamine 6 G-methanol solution was used as a fluorescent sample solution. The front zone of electrosomosis forms a reverse parabolic flow profile. The flow speed at the center of a cross-section of capillary was 0.4% lower than that at the near the wall. The progress of frontal zone while an applying pulsed electric field was observed. It was found that the growth and decay is very rapid, less than 1/15 second (which is equal to the time resolution in this experiment).View full abstractDownload PDF (6025K) -
Tamao ODAKE, Toru SATO, Takehiko KITAMORI, Tsuguo SAWADA1997 Volume 46 Issue 6 Pages 415-420
Published: June 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSPulsed UV laser-induced stationary wave capillary vibration (CVL) detection was applied to polymer solution capillary electrophoresis (CE) for a highly sensitive detection of nonderivatized DNA fragments. A waveguide excimer laser (smaller-sized and easier for practical use than a continuous-wave (CW) UV laser) was used as a CVL excitation source. A methylcellulose solution was used as a separation medium. It was found that the fluidity of a methylcellulose solution resulted in a long duration (>one day), as in the case of a free solution, even though the nano-second pulse energy was nearly one-thousand times as large as that of intensity-modulated CW laser light. Nonderivatized DNA fragments (ca. 60 μM) were used as a sample; both CE separation and CVL detection were performed. No fatal damage to the separation medium was observed. The lower detection limit (S/N=2) of the absolute amount was calculated to be 7 attomole, which showed that the sensitivity using a polymer solution was not inferior to that using a free solution. These results showed the feasibility of polymer-solution CE/pulsed CVL to the practical analysis of biopolymers, such as sequencing and DNA diagnosis.View full abstractDownload PDF (1279K) -
Hiroto OZAKI, Shigeru TERABE1997 Volume 46 Issue 6 Pages 421-427
Published: June 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSTwo methods were studied for on-line coupling between micellar electrokinetic chromatography (MEKC) and mass spectrometry (MS). A high-molecular-mass surfactant, diisobutylene-maleic acid copolymer sodium salt (DMA), was used as a new pseudo-stationary phase with an electrospray ionization interface. A DMA micelle functioned successfully as a pseudo-stationary phase, and showed significantly different selectivity for naphthalene derivatives in compared with butyl acrylate/butylmethacrylate/methacrylic acid copolymer sodium salt. Five standard compounds (phenyltrimethylammonium chloride, l-naphthylamine, quinine sulfate, tetraphenylphosphonium chloride and octaoxyethylene dodecanol) were separated by MEKC and detected by MS with DMA. An atmospheric pressure chemical ionization interface (APCI) was used for a conventional MEKC system using sodium dodecyl sulphate and sodium cholate.View full abstractDownload PDF (1347K) -
Hideki SASAKI, Jun YONEKUBO1997 Volume 46 Issue 6 Pages 429-437
Published: June 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSIn electromigrative sample introduction of capillary electrophoresis, the actual response obtained from an experiment does not correspond with the expected response calculated using a theoretical formula; also, its linearity on a calibration curve is not good compared with hydrodynamic sample introduction. The relationship between the responses and factors (concentration, sample volume in the vial, number of injections, sample matrix), which the pointed to a change in the total amount of injection volume in theoretical formula, was studied. This non-linear relationship can explain electrochemically by introducing the following equation to each theoretical formula: (1) μi=λi/∧eqF, ∧eq=ΣCiλi, (2) dQt=-aQt/V·dt; here μi is the electrophoretic mobility of ion-i, λi is the ionic equivalent conductance of ion-i, ∧eq is the equivalent conductance of an ionic solution, F is the Faraday constant, Qt is the number of ions existing in the vial at time t, dQt is the amount of the decrease in an infinitesimal time, and V is the volume filled in the vial. This scheme suggests that adding salts in order to increase the conductivity to samples provides a linear relationship between the concentrations and responses. According to this suggestion, the result from practical anion standards analysis showed a good linear relationship (r2>0.998).View full abstractDownload PDF (1773K) -
Takao FUKUMOTO, Hitoshi WATARAI1997 Volume 46 Issue 6 Pages 439-445
Published: June 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSFour kinds of pesticides (MEP, IBP, MCP, and PCNB) were separated by the capillary electrophoresis with some o/w microemulsions (μE-CE). In order to obtain information concerning the separation and/or migration mechanism μE-CE was carried out. The longest migration time for MCP was found in the case of surfactants with a sulfonate group, while the use of ones with a sulfate group led to the shortest migration time for MCP. The characteristic effect of the surfactants on the migration of MCP suggested a specific interaction with the interface of the microemulsion droplets. To obtain more detailed information about the microenvironment of the organophosphorus pesticides incorporated into the microemulsion, 31P-NMR measurement was carried out. It was found that a adsorption on the interface of the droplet contributed to a predominant interaction between the microemulsion and MEP, while in IBP the distribution into the droplet played an important role.View full abstractDownload PDF (1492K) -
Kayoko KATO, Takaho WATANABE, Yoshihiro YOSHIMURA, Hiroyuki NAKAZAWA1997 Volume 46 Issue 6 Pages 447-451
Published: June 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA chiral separation method of racemic nicardipines used as a calcium antagonist by capillary electrophoresis using various derivatives of cyclodextrin was studied. The separation of racemic nicardipine hydrochloride was carried out with a 20 mmol/l Tris-phosphoric acid buffer (pH 2.5) by adding 0.1 % methyl hydroxyethyl cellulose and various cyclodextrin. Since the optimum separation was achieved with the addition of ο-m-β-CD, the migration times of d-form and l-form were 24.5 and 25.2 min, respectively. Good reproducibility with a relative standard deviation of 3.0% was obtained tor migration time of nicardipine as the results of 10 replicate determinations. The racemic nicardipine was completely separated under optimum conditions with a separation factor of 1.029. A linear correlation between the peak height and the concentration of nicardipines was obtained within the range of 451500 pg as an absolute quantity (r=0.9998). The optical purity of racemic nicardipine in a tablet could be determined without any complicated pretreatment. The present method is applicable for the routine analysis of nicardipine preparations.View full abstractDownload PDF (914K) -
Hidetoshi ARAKAWA, Akio TSUJI, Masako MAEDA1997 Volume 46 Issue 6 Pages 453-459
Published: June 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSCapillary electrophoresis (CE) with a sieving buffer containing carboxymethyl cellulose (CMC) and dextran sulfate has been developed to analyze polymerase chain-reaction (PCR) amplified samples containing primers (oligonucleotide of about 1030 base), dNTPs (deoxy ATP, deoxy GTP, deoxy CTP, deoxy TTP) and the PCR product (DNA fragments of about 601000 bp) of interest. We primarily studied various cellulose derivatives (carboxymethyl cellulose sodium C6H7O2(OH)x(OCH2COONa)y)n n=1050 and n=500, Hydroxypropylmethyl cellulose) as a sieving material. Although separation using only CMC (n=500) could separate double-strand DNA fragments of φX174 RF DNA/Hae III digest and PCR reagents, the separation was insufficient to determine the DNA size of the PCR product. However, the separation can be improved extremely by adding dextran sulfate to the CMC solution. The optimal condition of this separation system with CMC as sieving materials and dextran sulfate as an adjunct was studied. The optimal condition was determined to be as follows; a running buffer of 25 mmol/l tris-glycine buffer (pH 8.4) containing 0.5% carboxymethyl cellulose - Na (n=500), 2.5% dextran sulfate-Na salt (MW: 8000) and 5 mmol/l EDTA. The fused-silica capillary tubing (42 cm (20 cm to the detector)×50 μm i.d.) non-coated with acrylamide solution was used. Electrophoresis was performed by 8 kV at 30°C. With this CE system, DNA. fragments (721353 bp) and the PCR product could be completly separated. The efficiency of this CE was shown by the large number of theoretical plate per meter: 1.8×105 and 2.5×105 for 118 by and 310 bp. This CE system can directly analyze PCR products from a reaction mixture without a purification step.View full abstractDownload PDF (1202K) -
Koji TAKAHASHI, Toshihiko IMATO, Nobuo URA1997 Volume 46 Issue 6 Pages 461-466
Published: June 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA poly(N-vinylpyrrolidone) (PVP) solution was used as a running buffer solution of capillary electrophoresis (CE) for the separation of catechol derivatives. No improvement in the separation efficiency between the cationic catechol derivatives, such as dopamine and epinephrine, was observed when a phosphate buffer solution containing PVP was used as the running buffer. This may have been due to a weak interaction of the cationic catechol derivatives with PVP. On the other hand, the separation efficiency between anionic catechol derivatives, such as caffeic acid, DOPAC including ascorbic acid, was greatly improved by the addition of PVP to the phosphate buffer solution, compared with the buffer solution without PVP. The improvement in the separation efficiency was due to the difference in the interaction of the solutes with PVP. The mobility of the anionic solutes in the presence of PVP, which was calculated from the migration times of the solutes and a neutral marker, increased in the order caffeic acid<DOPAC<ascorbic acid. This sequence suggests that the interaction of the solutes with PVP is larger in the order ascorbic acid<DOPAC<caffeic acid. The formation constants of the PVP complex with the solutes were estimated from the relationship between the PVP concentration in the running buffer and the mobility of the solutes obtained in this work.View full abstractDownload PDF (1221K) -
Toshio TAKAYANAGI, Eiko WADA, Shoji MOTOMIZU1997 Volume 46 Issue 6 Pages 467-475
Published: June 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSIon-association reactions in an aqueous solution between monovalent aromatic anions and quaternary ammonium ions were analyzed by means of the electrophoretic mobility. The electrophoretic mobility of analytes, such as phenolate, benzoate, benzenesulfonate, 1, 3-benzenedisulfonate, 1- and 2- naphtholate, 1- and 2- naphthalenecarboxylate, and 1-and 2- naphthalenesulfonate, was obtained by capillary zone electrophoresis. The electrophoretic mobility of analyte anions decreased with increasing the concentrations of the quaternary ammonium ions added in migrating solutions. The change in the electrophoretic mobility was analyzed to obtain the ion-association constants (Kass) by a nonlinear least-squares analysis method, as well as linear-square analysis methods. The obtained ion-association constants were larger in the anions possessing naphthalene ring than in those possessing benzene ring. The values of Kass became larger when more bulky cations were used as a pairing ion, indicating that the hydrophobicity of ions contributed to the ion associability. The ion associablities of β-substituted naphthalene isomers were larger than those of the α-substituted type, which agreed with the acid-dissociation property of the anions. The difference in the Kass values among functional groups was small, compared with ion-pair extraction constant (Kex) of the ion associates.View full abstractDownload PDF (1845K) -
Toshio SUZUKI, Hitoshi HOSHINO, Takao YOTSUYANAGI1997 Volume 46 Issue 6 Pages 477-482
Published: June 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe potential of capillary electrophoresis (CE) has been demonstrated for the analysis and characterization of humic substances (fulvic and humic acids). Humic substances were effectively separated by capillary gel electrophoresis (acrylamide gel CGE) and CE with cellulose derivative solutions using a 50 mM tris-borate buffer (pH 8.3) with 2 mM EDTA, or 5% polyvinylpyrrolidone (PNVP). They were detected by UV absorption at 260 nm and by emission at 490 nm (excitation at 390 nm). The using these gel systems leads to the separation of humic substances into two fractions, which comprise lower-molecular weight components as well as higher ones. The addition of iron (III) chloride resulted in a decrease in the peak of the lower molecular-weight components, which most likely arose from an aggregation of the lower-molecular weight fraction due to binding bond formation through the hydrolyzed Fe(III) ion. When sodium hypochlorite solution was added to the humic substance, some peaks decreased with increasing the residual chlorine concentrations. Therefore, the gel-mode CE enables one to monitor the reaction behavior as well as the fate of humic substances in an aquatic system in relation to the binding of metal ions and the oxidation processes.View full abstractDownload PDF (1281K) -
Shin-ichi WAKIDA, Sahori TAKEDA, Shin-ya MIYAZAKI, Yoshinori YAKUSHIJI ...1997 Volume 46 Issue 6 Pages 483-490
Published: June 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA high-performance gel electrophoresis for organic substances in environmental water using a polymer-based sieving media was investigated as an alternative separation method for a conventional high-performance gel-permeation chromatography. Effective separation conditions were investigated, as shown in the following. A sample was injected with electromigration (15 kV, 60 s), separated in a polyethyleneglycol coating capillary (DB-WAX; 0.1 mm i.d.×40 cm, effective length 32.5 cm) filled with a 0.1 M Tris-CHES buffer solution containing 0.5% methylcellulose with an applied voltage of 15 kV and detected selectively at 254 nm using a mercury lamp. We found descrimination of humic substances, such as a humic acid and fluvic acid, from the peak pattern of an electropherogram. We also obtained a several-peak separation of concentrated lake water samples within 6 min, and could estimate the main peak assignment using the above method.View full abstractDownload PDF (1333K) -
Yoshinobu AKADA, Nobuyuki ISHII1997 Volume 46 Issue 6 Pages 491-494
Published: June 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA simultaneous determination of berberine-type alkaloids (coptisine, berberine and palmatine) in Coptis Rhizome and Phellodendri Cortex water extracts was investigated by capillary electrophoresis. Free-zone capillary electrophoresis in 100 mM phosphate buffer at pH 8.5 gave complate separation of three alkaloids within 20 min. A sample solution was introduced by the hydrostatic method (10 s) and on-column detection was performed at 214 nm. The calibration curves of each alkaloid gave good linearities over the concentration range at 420 μg ml-1. Coptisine, berberine and palmatine in crude drug water extracts were determined with good reproducibility.View full abstractDownload PDF (728K) -
Sanyo HAMAI, Hiroshi WATANABE1997 Volume 46 Issue 6 Pages 495-498
Published: June 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSBy means of capillary electrophoresis, the equilibrium constants (K) for the formation of 1:1 inclusion complexes between β-cyclodextrin and 1- and 2-naphthalenesulfonates in aqueous buffer solutions of pH 7.3 were evaluated to be 190 ±20 and 480±20 M-1, respectively. From an analysis of the absorbance change upon adding β-cyclodextrin, the K value for 2-naphthalenesulfonate was evaluated to be 220±30 M-1, which is about half that obtained from capillary electrophoresis. The K value for 1-naphthalenesulfonate could not be estimated from the absorbance change because it was very small at even the highest β-cyclodextrin concentration. In this respect, the method using capillary electrophoresis prevails over the method of using absorbance changes.View full abstractDownload PDF (689K) -
Hirofumi KIKKAWA, Hisanori IMURA, Kousaburo OHASHI1997 Volume 46 Issue 6 Pages 499-502
Published: June 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe electrophoretic mobilities (μe) of phenol and chlorinated phenols were determined using a fused-silica capillary tube (50 μm i. d. and 75 cm long) at pH 612 and 21°C. The experimental conditions, such as the sample and buffer (phosphate and carbonate) concentrations and the high voltage, were optimized in order to obtain a reproducible μe. The electric mobility of anions (μA-) and the pKa of phenols were determined by applying a least-squares method based on the equation μe=μA-/(1+[H+]/Ka) to the data for μe vs. pH plots. The μA- values were found to increase in the following order: phenol<2-chlorophenol (CP)<3-CP<2, 6-dichlorophenol (DCP)<2, 5-DCP≤4-CP<3, 5-DCP<2, 4, 5- trichlorophenol<2, 3, 4, 6-tetrachlorophenol. It was found that the order of μA- among the geometrical isomers of CPs as well as DCPs agrees with that of pKa of the respective isomers.View full abstractDownload PDF (720K) -
Shunitz TANAKA, Kokoro KODAMA, Masanobu MORI1997 Volume 46 Issue 6 Pages 503-507
Published: June 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe migration behavior of biotin and biotin relatives was investigated by capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC). By CZE, biotin, lipoic acid and HABA were migrated as negatively charged species after the electroosmotic flow (EOF), and were separated adequately in the pH range of 7.59.0. However, biocytin, biotin hydrazide and iminobiotin could not be completely separated, because these compounds are electrically, neutral in the buffer solution, and were eluted at a similar velocity as the EOF. The condition of CZE at lower pH required a longer time for the elution of every peaks, and brought about a broadening of the peaks. The migration behavior of biotin relatives was also investigated by MEKC using sodium dodecyl sulfate (SDS). The migrating velocities of biocytin, biotin hydrazide and iminobiotin, which are electrically neutral, were controlled by an interaction with the micelle of SDS. From the relationship between the capacity factors and the SDS concentration, the distribution coefficients for these compounds were evaluated. At an SDS concentration of 0.175 M, a complete separation of six biotin relatives was achieved. The separation of biotin and biotinsulfone was also investigated by CZE and MEKC.View full abstractDownload PDF (824K) -
Jinghua ZHANG, Akira OKUBO, Sunao YAMAZAKI1997 Volume 46 Issue 6 Pages 509-511
Published: June 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA simple and rapid determination method for betaine aldehyde in plants was developed by capillary electrophoresis (CE). After betaine aldehyde was converted to the stable p-nitrobenzyl oxime, the reaction mixture was applied directly to CE. A low pH of around 3 of the migration buffer, which lowers the electroosmotic flow, was found to be favorable for the migration of positively charged compounds. This resulted in a high separation not only between the oximes, but also between the reagent and products. This also gave another advantage of omitting a pretreatment procedure of the reaction mixture. Betaine aldehyde oxime was well determined by either 214 or 270 nm within 15 minutes. A good linearity was shown in concentrations ranging from 0.10 to 10.0 mM. The repeatability (n=5) of the migration time and the peak area were 1.11 % and 5.62% as RSD, respectively. The method was applied to barley and common bean samples cultured with or without salt-stress, and proved to be suitable for the determination of a trace and unstable constituent, betaine aldehyde.View full abstractDownload PDF (581K) -
1997 Volume 46 Issue 6 Pages e1
Published: 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (127K)
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