Determination of Tramadol in Human Serum by Capillary Electrophoresis with the End-Column Electrochemiluminescence Detection

A capillary electrophoresis (CE) coupled with end-column electrochemiluminescence (ECL) detection method for the analysis of tramadol (TMD) has been investigated. ECL detection was working electrode biased at 1.2 V in a 20mmol·L-1 sodium phosphate buffer (pH = 8.0) containing 5 mmol·L-1 Ru (where bpy = 2,2’-bipyridyl). Linear correlation (r ≥ 0.997) between ECL intensity and drug concentration was obtained in the range 3 × 10-4 - 6 × 10-6 mol·L-1. The limits of detection (LODs) for tramadol in water was 3.012 × 10-8 mol·L-1(S/N = 3). The relative standard deviation values on peak size (10-5 mol·L-1 level) and migration time for the tramadol were 4.58% and 1.39% (n = 10), respectively. Applicability of the CE-ECL method to the analysis of human serum spiked with tramadol was

Interactions Between Thrombin and Natural Proudcts of Coreopsis tinctoria Nuttt. and Cistanche deserticola Ma. in Capillary Zone Electrophoresis

Aim A capillary zone electrophoretic method （CZE） was used to determine the interactions between natural products and thrombin. Methods Samples containing natural products and thrombin at various ratios were incubated at 25 ℃ and then were separated by CZE with Tris-acetate buffer at pH 7.2. Each run could be accomplished within 5 min. Results In CZE, the peak width broadened due to the affinity interaction between natural products and thrombin. Compared with positive and negative control, the natural products （CB-1, CB-2） from Coreopsis tinctoria Nuttt. interacted with thrombin; CB-3 from Coreopsis tinctoria Nuttt. and HC-1, HC-2, HC-3 from Cistanche deserticola Ma. did not bind to thrombin. Both qualification and quantification characterizations of the binding were determined. Conclusion The established method is capable of sensitive and fast determination of natural products and thrombin interactions, it can be employed as an alternative method.

Enantioseparation of Several PharmaceuticalRacemates with High PerformanceCapillary electrophoresis

With high performance capillary electrophoresis using -cyclodextrin or its deriveatives as the chiral selectors, five pairs of drug enantiomers were separated, The PH of the back- gmund electrolyte and the chiral selector concentrations were optimized; and the effect of organic modifier on separation of chlorpheniramine enantiomers was also inver

A Peptides Migration Model in capillary Zone Electrophoresis

A peptides migration model based on the principle of mechanics is presented in capillary zone electrophoresis (CZE). It is shown that the migration that the (tr) is a function of electric (Q), relative molecular mass (Mr), conformation parameter (Rc) of peptides and electrophoretic condition parameter(A). The conformation parameter is introduced to characterize multifarious shapes owing to the complex conlormation and the various kinds of macromolecules, where Rc≥1/3. The parameters A and Rc can be obtained from experimental data. The times of migration of the nine standard peptides were measured in pH 2.5buffer on different electrophoretic conditions in CZE. The experimental results agreed well with the theoretical prediction.

Separation of Nucleotides in Swine Tissues Using Capillary Zone Electrophoresis

Capillary zone electrophoresis has been applied to the analysis of nucleotides. The effects of buffer concentration. pH and other operating conditions on the separation were investigated and optimized. By using the method, separation and identification of nuclotides in swine tissues were completed.

Simultaneous Determination of Clonidine Hydrochloride,Hydrochlorothiazide, and Rutin in Zhenju Jiangya Tablet by Capillary Electrophoresis

Aim To develop a method for the determination of three drug components： clonidine hydrochloride, hydrochlorothiazide and rutin in Zhenju Jiangya tablet. Methods An uncoated capillary tube was used to analyze under 20 kV voltage at 20 ℃. The samples were introduced into the capillary tube by hydrodynamic mode applying 50 kPa for 5 s and detected at 210 nm. Results The linear ranges of clonidine hydrochlofide, hydrochlorothiazide, and rutin were 10 μg· mL^-1 - 100μg· mL^-1, 30μg· mL^-1 - 300 μg· mL^- 1, and 30μg · mL^-1 - 300μg · mL^-1, respectively. Inter-day and intra-day RSD were all below 10.5%. The recoveries were 94.96% for clonidine hydrochloride, 84.45% for hydroehlorothiazide, and 89.88 % for rutin. Conclusion Clonidine hydrochloride, hydrochlorothiazide, and rutin are baseline separated. The method is simple and rapid for simultaneous determination of the three drug components in Zhenju Jiangya tablet.

A New Capillary Electrophoresis Apparatus with Piezoelectric Ceramics High Voltage Source and Amperometric Detector

A new capillary electrophoresis apparatus was designed. Piezoelectric ceramics transformer technology was first applied in capillary electrophoresis, a high voltage and stable source was made. Amperometric detector was used in which the working electrode was closely opposite to the end of capillary. The apparatus was characterized in good reproducibility, safety and very low cost.

Simultaneous Detection of 13 Key Bacterial Respiratory Pathogens by Combination of Multiplex PCR and Capillary Electrophoresis

Objective Lower respiratory tract infections continue to pose a significant threat to human health. It is important to accurately and rapidly detect respiratory bacteria. To compensate for the limits of current respiratory bacteria detection methods, we developed a combination of multiplex polymerase chain reaction （PCR） and capillary electrophoresis （MPCE） assay to detect thirteen bacterial pathogens responsible for lower respiratory tract infections, including Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catorrholis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Mycoplasma pneumoniae, Legionella spp., Bordetella pertussis, Mycobacterium tuberculosis complex, Corynebactefium diphthefiae, and Streptococcus pyogenes. Methods Three multiplex PCR reactions were built, and the products were analyzed by capillary electrophoresis using the high-throughput DNA analyzer. The specificity of the MPCE assay was examined and the detection limit was evaluated using DNA samples from each bacterial strain and the simulative samples of each strain. This assay was further evaluated using 152 clinical specimens and compared with real-time PCR reactions. For this assay, three nested-multiplex-PCRs were used to detect these clinical specimens. Results The detection limits of the MPCE assay for the 13 pathogens were very low and ranged from 10-7 to 10-2 ng/μL. Furthermore, analysis of the 252 clinical specimens yielded a specificity ranging from 96.5%-100.0%, and a sensitivity of 100.0% for the 13 pathogens. Conclusion This study revealed that the MPCE with high specificity and sensitivity. This assay survey of respiratory pathogens. assay is a rapid, reliable, and high-throughput method has great potential in the molecular epidemiological.

p-Hydrazinobenzenesulfonic Acid Derivatives of Carbohydrates andTheir Capillary Zone Electrophoresis

p-Hydrazinobenzenesulfonic acid is explored as a novel ultraviolet labeling reagent for capillary electrophoresis (CE) of mono- and disaccharides. The labeling reaction takes less than 10 minutes and introduces both of absorption and charge groups into the sugars.

Chiral Separation of Chlorpheniramine by Capillary Electrophoresis *L

Aim To study the chiral separation of chlorpheniramine(Chp) by using a mixture of β CD and glutamate β CD as the chiral additive in CE. Methods Mixture of β cyclodextrin and glutamate β cyclodextrin was used as a chiral selector to the separation of chlorpheniramine. The effects of the concentrations of β cyclodextrin and glutamate β cyclodextrin, the voltage and the pH of buffers on the separation of chlorpheniramine were studied. Results The chiral recognization of the mixed chiral selector was better than that of a single selector. At pH below 4, the pH of buffers did not affect the separation and the separation of chlorpheniramine had good reproducibility. Conclusion Using a mixture of β CD and Glu β CD as chiral selector is useful for the enantioseparation of Chp in CE.

Capillary electrophoresis with electrochemiluminescence detection for the analysis of quinolone drugs and pharmacokinetics study

A novel method for the determination of two quinolone drugs norfloxacin （NOR） and levofloxacin （LVX） was described by capillary electrophoresis with electrochemiluminescence detection. The good relationship （r ≥ 0.9991） between peak area and concentration of analytes was established over two orders of magnitude. The limits of detection （LOD, S/N = 3） in standard solution are 4.8 × 10^-7 mol/L for NOR and 6.4 × 10^-7 mol/L for LVX, respectively. The limits of quantitation （LOQ, S/N = 10） in real human urine samples are 1.2 × 10^-6 mol/L for NOR and 1.4 × 10^-6 mol/L for LVX, respectively. The present method was successfully applied to the determination of NOR and LVX in human urine and the studv of oharmacokinetics of NOR.

Recent advances in screening of enzymes inhibitors based on capillary electrophoresis

Capillary electrophoresis with many advantages plays an important role in pharmaceutical analysis and drug screening. This review gives an overview on the recent advances in the developments and applications of capillary electrophoresis in the field of enzyme inhibitor screening. The period covers 2013 to 2017. Both the pre-capillary enzyme assays and in-capillary enzyme assays which include electrophoretically mediated microanalysis（EMMA） and immobilized enzyme microreactor（IMER） are summarized in this article.

Determination of Nicotine in Tobacco by Capillary Electrophoresis with Electrochemical Detection

A sensitive, simple and low-cost method based on capillary electrophoresis（CE） with electrochemical（EC） detection at a carbon fiber microdisk electrode（CFE） was developed for the determination of nicotine. Effects of de- tection potential, concentration and pH value of the phosphate buffer, and injection time as well as separation voltage were investigated. Under the optimized conditions： a detection potential of 1.20 V, 40 rnmol/L phosphate buffer（pH 2.0）, a sample injection time of 10 s at 10 kV and a separation voltage of 16 kV, the linear range obtained was from 5.0×10^-7 mol/L to 1.0×10^-4 mol/L with a correlation coefficient of 0.9989 and the limit of detection（LOD, S/N=3） obtained was 5.0×10^-8 mol/L. The method was also used to determine the nicotine in cigarettes. Nicotine amount ranged from 0.211 mg/g to 0.583 mg/g in the pipe tobacco of seven brands of cigarette and the amount in one ciga- rette varied from 0.136 mg/cigarette to 0.428 mg/cigarette.

A novel method for Co(Ⅱ) and Cu(Ⅱ) analysis by capillary electrophoresis with chemiluminescence detection

Based on the fact that some metal ions can catalyze the chemiluminescence(CL)reaction of luminol with K_3Fe(CN)_6,a novel capillary electrophoresis CL method was developed for the determination of Co(Ⅱ)and Cu(Ⅱ).The separation was carried out with a 10 mmol/L sodium acetate solution containing 0.8 mmol/L luminol and 2.0 mmol/Lα-HIBA(adjusted to pH 4.8 by HAc solution).The post-capillary reagent was 2.0 mmol/L K_3Fe(CN)_6 which was adjusted to pH 13.0 by NaOH solution.Under the optimum conditions,the detection limits(S/N=3)for Co(Ⅱ)and Cu(Ⅱ)were 7.5×10^(-11)mol/L and 7.5×10^(-9)mol/L,with the linear range of 7.5×10^(-9)mol/L to 1.0×10^(-6)mol/L and 7.5×10^(-8)mol/L to 5.0×10^(-5)mol/L, respectively.

Studies on Human Immunoglobulin G from GBS Patient (Ⅲ)-The Determination of Molecular Weight of Human Immunoglobulin G by Capillary SDS Gel Electrophoresis

Guillain-Barre syndrome (GBS) is considered to be an autoimmune disorder of peripheralnervous system. In this paper. capillary SDS gel electrophoresis was performed on neutral coatedfused-silica capillary to determine the molecular weight of purified IgG samples from GBS patient.

Simultaneous determination of flavonoids and anthraquinones in chrysanthemum by capillary electrophoresis with amperometry detection

A high-performance capillary electrophoresis with amperometry detection method （CE-AD） has been developed for the analysis of flavonoids and anthraquinones （emodin, kaempferol, apigenin, luteolin and rhein） in chrysanthemum. Under optimum conditions, these five analytes were base-line separated within 17 min using a borate-phosphate running buffer （1.5 ×10^-2 mol/L borate-3× 10^-2 mol/L phosphate running buffer, pH 9.0） at a working potential of ＋0.90 V （vs. SCE） and a separation voltage of 19 kV. The linear relationship between concentration and current response was obtained with detection limits （S/N = 3） ranging from 1.0 × 10^-7 to 2.1 × 10^-7 g/mL for all analytes. This proposed method was successfully used in the analysis of four kinds of chrysanthemum with relatively simple extraction procedures, the assay results were satisfactory.

Study on Rhizoma Chuanxiong based on capillary electrophoresis with amperometric detection

A high-performance capillary electrophoresis with amperometric detection(CE-AD) method has been developed for the analysis of seven bioactive ingredients,namely ferulic acid(FA),vanillin,vanillic acid,p-hydroxybenzoic acid,caffeic acid,gallic acid and protocatechuic acid,in Rhizoma Chuanxiong.The effects of several factors such as the acidity and concentration of running buffer,the separation voltage,the applied potential to working electrode and the injection time were investigated.Under the optimum condit...

Optimized Separation of Pharmacologically Active Xanthones from Securidaca inappendiculata by Capillary Electrophoresis

A capillary electrophoresis (CE) method has been firstly used for the separation of the therapeutically important xanthones from Securidaca inappendiculata. The separation of the nine xanthones was systematically optimized with respect to pH, concentration of running buffers, addition of sulfated b-CD, applied voltage and column temperature. Baseline separation was achieved for the nine xanthones in less than 15 minutes using a background electrolyte consisting of 200 mmol/L borate (pH 9.5) and 10 mmol/L sulfated b-CD.

Determination of Magnolol and Honokiol by Non-aqueous Capillary Electrophoresis

Two active principles in traditional Chinese medicine Magnolia officinalis, magnolol and honokiol, were successfully separated by means of nonaqueous capillary electrophoresis. The effect of the composition of a nonaqueous buffer on column efficiency and resolution, and the effect of acid additives on peak shapes were researched. The separation was conducted with a running buffer in a mixture of methanol/aeetonitrile/formamide （ volume ratio ： 1 ： 2 ： 2 ）, in which the concentrations of Tris, acetic acid, and water were 60 retool/L, 0. 04 mmol/L and 5% （ volume fration）, respectively, and the pH^＊ （apperent pH） of the running buffer was 8.96. Magnolol and honokiol were separated on baseline within 20 min. The relative standard deviation of the analytes＇ concentrations in the sample is 1.32% for magnolol and 1.60% for honokiol, and the recoveries of the spiked sample are 98.4% for magnolol and 98. 0% for honokiol, respectively.

Synthesis and Characterisation of Water-Soluble Carboxymethyl-Cyclodextrin Polymer as Capillary Electrophoresis Chiral Selector

The water-soluble carboxymethyl-cyclodextrin polymer (CM-CD polymer) was synthesized and used as capillary electrophoresis chiral selector. Verrapamil and thiopentorusodium were well separated using CM-CD polymer as chiral selector.