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Metallothioneins (MT) are a heterogeneous family of proteins coded from multiple linked genes whose individual expression can be readily determined at the transcriptional level by assay of mRNA using specific DNA probes targeted against the untranslated regions. Analysis of translated protein products is more challenging since sequence variation between MT isoforms can be as little as one in 61 amino...
As part of a comprehensive screening program on the separation of chiral drugs by capillary zone electrophoresis, we have investigated the enantio-separation of 54 drug racemates with β-cyclodextrin as a chiral solvating agent (CSA), thus complementing previous studies on 34 drug racemates. Fourteen out of the 54 analytes investigated have been separated into the enantiomers, yielding an overall success...
A new kind of sieving matrix is presented in this paper to allow satisfactory separation of DNA fragments in a relatively low viscous solution. When a certain amount of mannitol was added to cellulose solution not concentrated enough to separate PGEM-3Zf(+)/HaeIII standards well, a polymer solution with low viscosity but with very good separation effects was obtained. The separation result of this...
A new sensitive chemiluminescent detection method for capillary electrophoresis is described. Underivatized amines and amino acids were detected following capillary electrophoresis separation by their chemiluminescent reaction with Ru(bpy) 33+ generated in situ at 35 μm carbon fibers. Detection limits for triethylamine and proline were 5 and 3 fmol, respectively at a SNR of three...
A new electrochemical cell assembly with the combination of UV and amperometric detector (AD) based on their complementarity was described. A Nafion tubing junction was used to decouple the high voltage from the separation capillary in the rear of on-column UV detector. In this mode, the electroactive and inert compounds could be detected by UV and AD at the same time. Aromatic amines were determined...
A rapid and sensitive method is described for the detection of melatonin in rat pineal gland and melatonin tablets. Capillary electrophoresis (CE) with electrochemical detection (EC) was used. This method had high sensitivity and good reproducibility. The detection limit of melatonin was as low as 1.3x10 -9 mol/l (0.30 fg). There was a linear range of concentration from 3.9x10 - ...
A chemometric methodology was proposed to optimize the migration time, height equivalent to a theoretical plate and separation of a mixture of a series of imidazole compounds by capillary electrophoresis. The optimization process was based on a special polynomial from 9 or 18 preliminary experiments. This method connects a general simplex method to a computer. A simplex two or three optimization-capillary...
The ability of Chlorella vulgaris to accumulate heavy metals in solution (Mn, Cr, Ni, Zn and Cu) was investigated. Various parameters (algal biomass, pH and contact time of the algae with the sample) have been studied. Nine mg of algal biomass, pH 8 and 15 min of contact time, with 1 ppm of each metal, were the optimized conditions. At pH 8, the optimum value to rise the maximum binding, a fraction...
Capillary electrophoresis (CE) with end-column electrochemical detection (EC) of barbituric acid (BA) and 2-thiobarbituric acid (TA) has been described. Under optimum condition, BA and TA were separated satisfactorily, and a response of high sensitivity and stability was obtained at a detection potential of 1.25 V versus Ag/AgCl. Optimized end-column detection provides detection limit as low as 0...
The oxidation reaction kinetics of thiocyanate by excess hydrogen peroxide has been studied by using capillary electrophoresis. The paper illustrates for the first time the use of capillary electrophoresis in studying reaction kinetics and provides a non-laborious way to determine the rate law and the rate constant for the above reaction in the pH range 6-8. Standard solutions of thiocyanate were...
A simple and sensitive capillary electrophoretic method was developed for the separation and determination of Ziram and Zineb in boric acid buffer by direct UV absorbance detection at λ=254 nm. The separation is dependent on pH and nature of the buffer. The detection limits (S/N=3) are 1.88x10 -6 mol/l (0.57 μg/ml) and 2.48x10 -6 mol/l (0.68 μg/ml) for Ziram and Zineb, respectively...
In situ generated Ru(bpy) 33+ -based chemiluminescence (CL) detection will be shown to be compatible with micellar electrokinetic chromatography (MEKC) providing significant advantages over other Ru 3+ generation protocols. The CL reagent, Ru(bpy) 32+ is continuously added post-capillary to avoid precipitating the anionic surfactant used to enhance...
A method based on capillary electrophoresis with electrochemical detection (CE-ED) was developed for the determination of baicalein, baicalin and quercetin in Scutellariae Radix and its pharmaceutical preparations. The effects of some important factors such as the acidity and concentration of running buffer, separation voltage, injection time, and the potential of working electrode were investigated...
Peptide mapping has been widely used for the identification of modified proteins involved in certain diseases. Despite the fact that capillary electrophoresis (CE) has been shown to be a powerful tool for the separation and detection of tryptic peptide fragments after protein digestion, this technique lacks sensitivity for mapping proteins isolated in very small quantities from biological samples...
A micellar electrokinetic capillary chromatography (MECC) method for the separation of three active components, imperatorin (IM), isoimperatorin (IO) and scopoletin (SC), in Angelica dahurica Benth and its preparation was developed. The optimum separation for these analytes was achieved using 10 mM borate, 20 mM SDS and 10%(v/v) acetonitrile, with applied voltage of 22 kV. All experiments were performed...
Capillary electrophoresis with electrochemical detection (CE-ED) was employed for the determination of hypaphorine (an alkaloid) and four oligomeric stilbenes (including pallidol, kobophenol A, miyabenol C and (+)-α-viniferin) in Radix seu Cortex Caraganae Sinicae, the root of Caragana sinica (Buc'hoz) Rehd. The effects of several important factors were investigated to find optimum conditions. The...
The presence of selenium in the form of different species in environmental and biological samples receives an increasing attention due to better understanding of its bioavailability, toxicity and transport mechanism. For many years, gas and liquid chromatography have been extensively explored in speciation analysis of this element. Recently, capillary electrophoresis (CE) has made much progress in...
A fast and effective method to study the aquation of rhodium(III) chlorocomplex in hydrochloric solutions using capillary zone electrophoresis (CZE) is developed. At least five species, some of which seem to be oligomeric, are formed in solution during the aquation process at pH>1. The fast hydration of RhCl 63- makes this species impossible to detect. The first species detected...
A novel approach was developed for the separation and detection of a benzo[a]pyrene B[a]P-DNA metabolite (tetrol I-1) in the presence of DNA using CE and laser induced fluorescence. Tetrol I-1 in the presence of DNA is intercalated and undergoes fluorescence quenching. Thus, an equilibrium is established between the intercalated tetrol I-1 and the uncomplexed tetrol I-1. It is only the uncomplexed...
The type-I ribosome-inactivating protein trichosanthin (TCS) has a broad spectrum of biological and pharmacological activities, including abortifacient, anti-tumor and anti-human-immunodeficiency-virus (anti-HIV). In this study, circular dichroism (CD) and capillary electrophoresis were used for the first time to study TCS and its two TCS mutants of Y55G TCS (tyrosine 55 converted to glycine) and...
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