高效毛细管区带电泳法快速测定尿液中的肌酐

建立了一种快速测定尿中肌酐浓度的高效毛细管电泳方法。利用非涂层石英毛细管(64.5 cm×50μm i.d),以pH 2.5,0.1 mmol/L H3PO4作为电泳缓冲液,检测波长191 nm,用0.05 Pa压力进样4 s,在电压16 kV快速分离尿液中的肌酐,采用外标法定量。肌酐的迁移时间约为5.5 min,肌酐浓度在34.5~8840μmol/L范围内呈良好的线性(r2=0.999)。平均日内精密度为2.5%,日间精密度为3.0%。回收率94.1%~99.0%。与全自动生化分析仪碱性苦味酸速率法相比有良好的相关性(r=0.990,n=56)。高效毛细管电泳法测定尿肌酐可应用于临床样品的检测。     

毛细管区带电泳法同时分离测定香兰素和邻位香兰素异构体

建立了同时测定香兰素和其异构体邻位香兰素的毛细管区带电泳法(CZE)。考察了缓冲溶液的种类、浓度和pH以及分离电压等因素对分离结果的影响。在缓冲溶液为50 mmol/L硼砂-150 mmol/L磷酸氢二钠(pH 7.5)、分离电压15 kV的优化条件下,6 min内即可实现分离。香兰素和邻位香兰素在10～240 mg/L范围内线性关系良好,相关系数分别为0.9999和0.9997;方法的检出限均为1.0 mg/L (信噪比为3);样品的加标回收率为99.4%～101.2%,相对标准偏差为0.19%～0.73%。该方法操作简单、快速,已应用于实际样品的分析,并获得了令人满意的结果。     

Simultaneous determination of sulfamethoxazole and trimethoprim in human plasma by capillary zone electrophoresis

A capillary electrophoretic method for the simultaneous determination of sulfamethoxazole and trimethoprim in plasma was developed. Sulfamethoxazole and trimethoprim extracted from human plasma with ethyl acetate were analyzed at 20 kV and 25 degrees C using 15 mm phosphate buffer (pH 6.2) as the electrolyte. The detection was by UV at 220 nm. The run time was 8.0 min and the limit of quantification was 10.00 microg/mL for sulfamethoxazole and 2.00 microg/mL for trimethoprim. The recovery was >99% for both compounds. This method enabled the detection of sulfamethoxazole and trimethoprim in plasma of patients after oral ingestion of their combined formulation. The present simple and rapid method is applicable to drug monitoring in immunocompromised patients who are taking the combined formulation of these compounds for the treatment or prophylaxis of Pneumocystis carinii pneumonia.     

Simultaneous determination of flavonoids in chrysanthemum by capillary zone electrophoresis with running buffer modifiers

Despite the separation efficiency of capillary electrophoresis (CE) is much higher than other chromatographic methods, it is sometimes difficult to perfectly separate the complex ingredients in biological samples. One possible and simple way to develop the separation effect in CE is to add some modifiers in the running buffer. In this paper, the suitable running buffer modifiers were explored to simultaneously separate and detect six typical flavonoids (apigenin, luteolin, kaempferol, quercetin, (+)-catechin and (−)-epicatechin) which are the main active ingredients in chrysanthemum by capillary zone electrophoresis with amperometric detection (CZE-AD). It was found that when β-cyclodextrin (β-CD) and the mixture of methanol and ethanol were used as running buffer modifiers, a baseline separation of the six analytes could be accomplished in less than 20 min and the detection limits were as low as 10⁻⁷ or 10⁻⁸ g ml⁻¹. Other factors affecting the CZE separation, such as working potential, pH value and ionic strength of running buffer, separation voltage and sample injection time were extensively investigated. Under the optimum conditions, a successful practical application on the determination of chrysanthemum samples confirmed the validity and practicability of this method.     

Simultaneous determination of multiple constituents in real beer samples of different origins by capillary zone electrophoresis

Simultaneous determination of alcohols, amines, amino acids, flavonoids, and purine and pyrimidine bases in bottled beer samples directly without any pre-treatment was carried out by capillary zone electrophoresis with diode-array detection. Electrolyte conditions such as pH, composition and concentration of the buffer, working voltage and type and time of injection were checked. The best separation of the cited analytes was achieved in 70 mM sodium borate solution and pH 10.25. The detection limits were from 2.1 to 5.6 mg L^–1 for the 18 compounds studied. The developed method is rapid, sensitive and quantitative and has been applied to seven types of international bottled beers of different origins bought locally.     

Simultaneous determination of noradrenaline and dopamine in Portulaca oleracea L. by capillary zone electrophoresis

A simple and rapid capillary electrophoretic method was developed for the simultaneous determination of noradrenaline (NA) and dopamine (DA) in Portulaca oleracea L. The buffer solution used in this method was 40 mM tris (hydroxymethyl) aminomethane (Tris)-H3PO4 at pH 2.00 containing 15% methanol. The effects of pH value, organic modifier, and applied voltage were investigated. The linear ranges of NA and DA were 0.5-100 microg/mL (r=0.9952) and 6.25-200 microg/mL (r=0.9992), respectively. The relative standard deviations of the corrected peak area were 6.73% and 4.26%, respectively. NA and DA in Portulaca oleracea L. were simultaneous determined successfully within 5.6 min. In this way, the contents of NA and DA in different parts (stem, leaves, and seeds) of P. oleracea L. and in different extracts of leaves with different solvents (distilled water, 50% methanol, and methanol) were studied.     

Simultaneous determination of anthraquinones in Rhubarb by pressurized liquid extraction and capillary zone electrophoresis

Rhubarb, a well-known Chinese herbal medicine, is also used in Europe and other places of the world. Anthraquinones derivatives are thought to be the major active components. A pressurized liquid extraction (PLE) and capillary zone electrophoresis (CZE) separation were developed for simultaneous determination of five anthraquinones including aloe-emodin, emodin, chrysophanol, physcion, and rhein in Rhubarb. The effects of the experimental variables on PLE and CZE have been optimized. The optimum conditions of PLE were: solvent, methanol; temperature, 140 degrees C; particle size, 0.13-0.2 mm; static extraction time, 5 min; pressure, 1500 psi; and one extraction. The best separation of the five anthraquinones could be obtained using 50 mM borate buffer (pH 8.2) containing 25% isopropyl alcohol and 25% acetontrile as modifier, while the separation voltage was 25 kV and the temperature was at 20 degrees C. The method developed is accurate, simple, and reproducible, and could be used for quality control of Rhubarb and its medical preparations.     

Simultaneous determination of psychotropic drugs in human urine by capillary electrophoresis with electrochemiluminescence detection

Amitriptyline, doxepin and chlorpromazine are often used as psychotropic drugs in treatment of the various mental diseases, and are also partly excreted by kidney. This work developed a simple, selective and sensitive method for their simultaneous monitoring in human urine using capillary electrophoresis coupled with electrochemiluminescence (ECL) detection based on end-column ECL reaction of tris-(2,2′-bipyridyl)ruthenium(II) with aliphatic tertiary amino moieties. Acetone was used as an additive to the running buffer to obtain their absolute separation. Under optimized conditions the proposed method displayed a linear range from 5.0 to 800 ng mL⁻¹ for the three drugs with the correlation coefficients more than 0.995 (n = 8). Their limits of detection were 0.8 ng mL⁻¹ (3.6 fg), 1.0 ng mL⁻¹ (4.5 fg) and 1.5 ng mL⁻¹ (6.8 fg) at a signal to noise ratio of 3, respectively. The relative standard deviations for five determinations of 20 ng mL⁻¹ amitriptyline, doxepin and chlorpromazine were 1.7%, 4.2% and 3.6%, respectively. For practical application an extract step with 90:10 heptane/ethyl acetate (v/v) was performed to eliminate the influence of ionic strength in sample. The recoveries of amitriptyline, doxepin and chlorpromazine at different levels in human urine were between 83% and 93%, which showed that the method was valuable in clinical and biochemical laboratories for monitoring amitriptyline, doxepin and chlorpromazine.     

Simultaneous determination of substrate and product in the process of preparation of valienamine by capillary zone electrophoresis

A simple and rapid CZE method was established for the simultaneous determination of valienamine, acarbose and validamycin A, using a 20‐kV CZE with the detection wavelength of 193 nm and 50 mM phosphoric acid–20 mM Tris (pH 5.3) as a running buffer. The calibration curves of valienamine, acarbose, and validamycin A showed a good linear relationship at a concentration range of 5–1000 μg/mL. The detection limits of valienamine, acarbose, and validamycin A were 0.3, 0.6, and 0.6 μg/mL, respectively, and the average recoveries of each of the above were 99.9, 99.5, and 100.3%. The method has been successfully applied for simultaneous determination of substrate and product in the process of preparation of valienamine.     

Simultaneous determination of nine flavonoids in Anaphalis margaritacea by capillary zone electrophoresis

A capillary zone electrophoresis method was developed for simultaneous determination of nine flavonoids, including two rare flavonols, in Tibetan medicine Anaphalis margaritacea. Baseline separation was performed at pH 9.6 with 25 mM Na₂B₄O₇ and 10 mM NaH₂PO₄ buffer solution, 20 kV as driving voltage and 275 nm as detection wavelength. Repeatability tests showed that the R.S.D. of both intra- and inter-day migration times and peak areas were less than 5%. Recovery results ranged from 87.9% to 106.1%. Samples of A. margaritacea extracts were analyzed using the validated method, which is useful for its quality control.     

Simultaneous determination of tetracyclines in poultry muscle by capillary zone electrophoresis

A capillary zone electrophoresis method with UV detection was developed for the simultaneous detection and quantification of three tetracyclines in chicken meat samples: tetracycline (TC), oxytetracycline (OTC) and doxycycline (DOC). The separation conditions were: a running buffer containing 30 mM sodium phosphate, 2 mM EDTA disodium salt and 2.5% 2-propanol, pH 12.0, a 5 s hydrodynamic injection and a 14 kV separation voltage. Two different clean-up methodologies were employed: solid-phase extraction with C₁₈ cartridges and ion exchange with Amberlite XAD7 resin. Analytes were detected at 360 nm in less than 12 min. LODs ranged from 61 μg kg⁻¹ for OTC to 68 μg kg⁻¹ for DOC with C₁₈ cartridges, and 81 μg kg⁻¹ for DOC to 89 μg kg⁻¹ for TC with Amberlite XAD7 resin. The recoveries for TC, OTC and DOC obtained by both methods were between 85 and 95%, and the peak area repeatability for all of the samples was below 5% in all cases. Twenty-four samples of commercial chicken drumsticks were examined with both clean-up methodologies. In nine cases (37.5%) TC was detected, in a range from 197.8 to 2564.3 μg kg⁻¹, and in seven cases (29.2%) OTC was detected in a range from 83.0 to 2049.3 μg kg⁻¹. DOC was not detected in any of the tested samples. This method would be useful for the routine monitoring of TCs residues in poultry muscle.     

Selective and rapid determination of biogenic amines by capillary zone electrophoresis

Summary A rapid separation of 21 amines by high-performance capillary zone electrophoresis with indirect photometric detection is presented. The electrolyte is based on copper(II) as primary constituent. Factors affecting the separation by this electrolyte have been investigated and include the composition of the buffer, the voltage, the temperature and the mode of injection. External calibration was used to characterize the analytical response to each amine. The detection limits were approximately 0.05 μg mL⁻¹ for almost all the amines. After electrokinetic or hydrodynamic injection calibration plots of peak area against concentration were linear between 0.05 and 10 μg mL⁻¹. The method has been applied to the analysis of biogenic amines in synthetic samples; the recoveries of the amines from such samples, determined by the standard addition technique, were in the range 90 to 110%.     

毛细管区带电泳法测定粉针剂中头孢拉定的含量

用毛细管区带电泳法测定头孢拉定的含量 ,未涂层毛细管柱 (75 μm×48.5cm ,有效长度 40cm) ,电压 2 8kV ,检测波长 2 3 0nm ,温度 2 0℃ ,进样 5×1 0 3Pa× 3s。运行缓冲液为 2 5mmol/L硼砂缓冲液。方法的线性范围 3 1 .2 2μg/mL～ 749.2 8μg/mL ,检测限为 1 .1 7μg/mL。     

Simultaneous determination of first-line anti-tuberculosis drugs by capillary zone electrophoresis using direct UV detection

An alternative methodology for simultaneous analysis of ethambutol, isoniazid, rifampicin and pyrazinamide in pharmaceutical formulations by capillary zone electrophoresis under UV direct detection with an analysis time of 8.0 min is proposed. Background running was based on the effective mobility curve of the analytes and an optimum separation condition was achieved using a 3³ Box-Behnken design, with Brij 35, Cu²⁺ and acetic acid/sodium acetate buffer as factors. An electrolyte consisting of 50.0 mmol L⁻¹ of acetic acid/sodium acetate buffer, 12.5 mmol L⁻¹ of CuSO₄, and standard and sample solutions prepared in 2.00 mmol L⁻¹ of Brij 35 and 12.5 mmol L⁻¹ of CuSO₄ were optimized. After evaluating validation parameters, the method was successfully applied to the analysis of samples in the form of tablets and sachets.     

Separation and simultaneous determination of quinolone antibiotics by capillary zone electrophoresis

Summary The potential of capillary zone electrophoresis has been investigated for the separation and quantitative determination of some quinolone antibiotics. The influence of different conditions, such as the nature and concentration of the electrophoretic electrolyte, on migration time, peak symmetry, efficiency and resolution was studied. A buffer consisting of 100mm HEPES adjusted to pH 8.5 containing 10% (v/v) acetonitrile was found to furnish a very efficient and stable electrophoretic system for the separation of exoxacin, ciprofloxacin, ofloxacin, oxolinic acid, nalidixic acid and pipemedic acid. A linear relationship between concentration and peak area for each compound was obtained in the concentration range 0.25–40 μg mL⁻¹; detection limits were approximately 0.25 ng mL⁻¹. It was demonstrated that the method can be used for the simultaneous determination of these six antibiotics in serum and urine samples.     

Simultaneous determination, by capillary zone electrophoresis, of multiple components of different industrial products

Summary Four parabens (esters of 4-hydroxybenzoic acid), effective preservatives against the growth of bacteria, yeast, and mold in numerous industrial products, have been used in this work as model compounds to demonstrate the resolving power of capillary electrophoresis (CE). The simultaneous determination of methyl-(MP), ethyl-(EP), propyl-(PP), and butylparaben (BP) was achieved by capillary zone electrophoresis (CZE) with UV diode-array detection at 294 nm. When run voltage, temperature, and electrolyte concentration and pH were optimized the most effective separation was achieved within 7 min by use of 50 cm (effective length) fused silica capillary tubing and operation at 25kV and 20°C. Background electrolyte comprising 35 mM tetraborate buffer adjusted to pH 10.0 gave the best results. The limits of detection of the optimized method ranged from 0.65 μg mL⁻¹ for BP to 0.81 μg mL⁻¹ for MP; the relative standard deviation was between 0.35 and 0.50%. These results showed that the method enables the determination of the four parabens in commerially available cosmetic and pharmaceutical preparations containing some of the parabens and in an unidentified canned berry fruit juice.     

Simultaneous determination of uranium carbide dissolution products by capillary zone electrophoresis

Separation and simultaneous determination of a number of organic acid anions (oxalate, mellitate, trimellitate and benzoate) and U(VI) with direct UV detection is developed for analysis of uranium carbide (UC) dissolution products by capillary zone electrophoresis (CZE). Reverse polarity mode is used. It is found that complex formation of U(VI) with carbonate, used as a carrier electrolyte, allows U(VI) to be determined, as negatively charged species, in a single run with organic acid anions. Some parameters such as pH value, composition of electrolyte and detection wavelength are optimized. Under the chosen conditions (carbonate buffer (ionic strength of 100 mM), pH 9.8, 0.15 mM tetradecyltrimethylammonium bromide (TTAB)) a complete separation is achieved. Calibration plots are linear in two ranges of concentration for U(VI) (∼1 × 10⁻⁵ to 1 × 10⁻³), mellitate and trimellitate (∼5 × 10⁻⁶ to 5 × 10⁻⁴), and about one range (∼1 × 10⁻⁴ to 5 × 10⁻³) for oxalate and benzoate. Accuracy of the procedure is checked by the “added-found” method in standard mixture solutions. Relative standard deviation is within the range of 2–10% and the recovery is in the range of 90–110%. This method is applied for the analysis of real UC dissolution samples.     

Separation and determination of chalcones from Carthamus tinctorius L. and its medicinal preparation by capillary zone electrophoresis

A new capillary zone electrophoresis (CZE) method was developed for simultaneous assay of four chalcones, hydroxysafflor yellow A, safflor yellow A, safflamin C, and safflamin A, in the Chinese herbal extract from Carthamus tinctorius L. The optimum buffer system was 30 mM borate buffer (Na2B407/HCl, pH 9.00) with 10% (v/v) methanol. The voltage was 15 kV and detection was at 270 nm. Regression equations revealed linear relationships (correlation coefficients: 0.9973, 0.9992, 0.9989, and 0.9996) between the peak area of each compound and its concentration. The within-day relative standard deviations of migration times and peak areas were < 1.53 and 4.14%, respectively. The effects of several CE parameters on the resolution were studied systematically. The contents of four chalcones in Carthamus tinctorius L. were successfully determined with satisfactory repeatability and recovery. The possibilities of using this method for the determination of chalcones in Chinese medicinal preparation was also tested.