Studies of Active Ingredients in Cough Syrup by Capillary Zone Electrophoresis with Amperometric Detection

The present paper covers a simple, reliable and reproducible method, based on capillary zone electrophoresis(CZE) with amperometric detection(AD), for the separation and the determination of ephedrine hydrochloride, promethazine hydrochloride and codeine phosphate. Under the optimal conditions, the three analytes were base-line separated completely within 16 min. Good linear relationships between the peak heights and the concentrations of the three analytes were obtained with the correlation coefficients better than 0 9993. The method was directly applied to the determination of the active ingredients in pharmaceutical preparations and the assay results were satisfactory.

Detection and Separation of Inorganic Cations in Natural, Potable, and Wastewater Samples Using Capillary Zone Electrophoresis with Indirect UV Detection

Capillary zone electrophoresis (CZE) is a sensitive and rapid technique for determining traces of inorganic cations in water samples. CZE with indirect UV-diode array detection (CZE-DAD) was utilized to identify several inorganic cations in natural, potable, and wastewater samples. A pH 4.35 background electrolyte system was employed and consisted of 15 mM imidazole, 8 mM malonic acid, 2 mM 18-crown-6 ether as complexing agents, 10% v/v methanol as an organic modifier with indirect absorbance reference at 214 nm. The CZE method involved electromigration injection at 5 kV for 5 s, a separation voltage of 20 kV at 25℃, and a detection wavelength of 280 nm. Six main cations (ammonium , potassium K+, calcium Ca2+, sodium Na+, magnesium Mg2+, and lead Pb2+) were tested, and all but lead, were detected in the water samples at concentrations between 0.03 and 755 ppm with a detection limit ranging between 0.023 and 0.084 ppm. The successful evaluation of the proposed methodology allowed us to reliably detect and separate six metal ions in different water samples without any pretreatment. All water samples were collected from Northern New York towns and the Raquette River water system, the third longest river in New York State and the largest watershed of the central and western Adirondacks.

Capillary Zone Electrophoresis with Amperometric Detection for Composition Analysis of Laminarin

The composition of laminarin was firstly determined by analyzing its hydrolysis monosaccharides with capillary zone electrophoresis-amperometric detection (CZE-AD). Under the selected optimum conditions, fucose, galactose, glucose, mannose and xylose, which are hydrolysis products of laminarin, could be perfectly separated within 20 min and showed significant current responses at copper electrodes. The linear ranges of fucose, galactose and glucose were from 1.0×10 -6 to 2.0×10 -4 mol·L -1, those of mannose and xylose were from 5.0×10 -6 to 2.0×10 -4 mol·L -1, and their detection limits were at 10 -7 mol·L -1 level (S/N=3). The molar ratio of fucose, galactose, glucose, mannose and xylose in laminarin was 10.5∶2.8∶1.0∶7.3∶3.4 and the purity of this polysaccharide leached by the introduced leaching method was 95.7%. Compared to usual UV-vis and other spectrometric methods, analyzing polysaccharide by this method has some merits of quickness, low-volume sampling, simple instrumentation, high sensitivity and high reproducibility.

Determination of strychnine and brucine in traditional Chinese medicine preparations by capillary zone electrophoresis with micelle to solvent stacking

A novel micelle to solvent stacking on-line sample preconcentration technique in capillary zone electrophoresis（MSS-CZE） has been developed to determine the strychnine and brucine in traditional Chinese medicine preparations.The optimal running buffer was 30 mmol/L H_3PO_4 containing 20%acetonitrile at pH 4.0.The sample matrix was 8 mmol/L H_3PO_4 containing 5 mmol/L sodium dodecyl sulfate（SDS） at pH 3.0.The established MSS-CZE method afforded more than 50-fold improvements in concentration sensitivity compared with typical CZE-UV analysis.The calibration curve was linear in the range from 0.2 to 15.0μg/ mL for both strychnine and brucine,with correlation coefficients of 0.9984 and 0.9976,respectively.The limits of detection（5/ N = 3：1） for strychnine and brucine were 0.02 and 0.05μg/mL,respectively.The MSS-CZE method has been successfully applied to the analysis of strychnine and brucine in Chinese medicinal preparations.

Determination of Four Active Ingredients in Vc Yinqiao Tablets by Capillary Zone Electrophoresis with Amperometric Detection

A simple, reliable and reproducible method, based on capillary zone electrophoresis with amperometric detection （CZE-AD）, has been developed for simultaneous determination of four active ingredients in Vc Yinqiao tablets including paracetamol, vitamin C, caffeic acid and chlorogenic acid. A carbon-disk electrode was used as working electrode and 0.95 V （versus SCE） was selected as detection potential. The optimal conditions of CZE experiment were 30 mmol·L^-1 borate solution （pH 9.5） as running buffer, 14 kV as separation voltage and 8 s （14 kV） as electro-kinetic sampling time. Under the selected optimum conditions, paracetamol, vitamin C, caffeic acid and chlorogenic acid could be perfectly separated within 22 min, and their detection limits （S/N=3） ranged from 5×10^-7 to 1 ×10^-6 mol·L^-1. This proposed method demonstrated good reproducibility with relative standard deviations of less than 3% for both migration time and peak current （n=7）. The utility of this method was demonstrated by monitoring a kind of compound medicine named Vc Yinqiao tablets and 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...

Determination of isoniazid and hydrazine by capillary electrophoresis with amperometric detection at a Pt-particle modified carbon fiber microelectrode

Capillary electrophoresis (CE)/electrochemical detection (EC) for the simultaneous determination of hydrazine and isoniazid has been developed. The electrochemical method uses a novel modified electrode dispersed with ultrafine platinum particles on the surface of a 30 mu m carbon fiber microelectrode. The unique characteristic of the Pt-particles modified carbon fiber microelectrode is its excellent stability. The current measurement for hydrazine is more sensitive than that of isoniazid. Selective determination of trace amount of free hydrazine in isoniazid and its formulation can be achieved at applied potential of 0.5 V.

Determination of Roxithromycin Tablets by Capillary Electrophoresis Employing Non-aqueous Media with Square-wave Amperometric Detection

A new method of determination for roxithromycin tablets by non-aqueous capillary electrophoresis (NACE) with square-wave amperometric detection was carried out. Several parameters affecting the NACE-AD determination were studied. The data was modified by spline wavelet least square (SWLS). The method is simple, rapid and highly reliable for routine analysis.

Amperometric Detection of Histamine and Amino Acid Neurotransmitters in Capillary Electrophoresis with Copper Microelectrodes

Copper microelectrodes were used in microvoltammetry to detect histamine and several amino acid neurotransmitters. High sensitivity was obtained through the use of copper microelectrodes, and detection limits of 50 nmol/L and 90 nmol/L were obtained for histamine and histidine, respectively. Furthermore, histamine and several amino acids neurotransmitters were firstly separated and detected by capillary electrophoresis with amperometric detection on copper microelectrodes. Mass limits of 490 amol and 440 amol were achieved for histamine and histidine, respectively, by using this mothod.

Electrochemical Determination of Salivary N-Acetylneuraminic Acid by Miniaturized Capillary Electrophoresis Coupled with Sample Stacking

Due to their important biological role as markers for different pathologies, sialic acid （SA） analyses are important for clinical research. In this work, a miniaturized capillary electrophoresis with amperometrie detection （mini-CE-AD） was developed for the determination of N-aeetylneuraminic acid （NANA）, which is the most widespread form of SAs. NANA was first oxidized by periodic acid in an acidic solution, and then the oxidation product β-formyl pyruvic acid was derivatized with electroactive 2-thiobarbituric acid （TBA） to form an electroactive NANA-TBA adduct, which could be readily determined by mini-CE-AD. The limit of detection （LOD） of NANA-TBA could achieve 0.50 μg/mL （1.6 μmol·L-1, S/N=3） based on an online enrichment approach of moving chemical reaction boundary. The proposed method was successfully applied to the analysis of NANA in human saliva, and the recoveries were in the range of 91.8%-109% with RSDs of 1.8%-3.9%. Due to its simple design and construction, low cost and portability, the mini-CE-AD device will possess more practicability in more field work as an alternative to conventional and microchip CE approaches.

Capillary Electrophoretic Determination of Jinggangmycin A in Formulations Using Direct UV Detection

A simple, fast and reliable method was developed for the analysis of jinggangmycin A （validamycin A） in commercial formulations. The running buffer used was acetate buffer （100 mmol/L, pH 4.7） with 15 kV as the applied voltage. The detection was achieved by using direct UV mode at 200 nm and the detection limit was 0.2 μg/mL. Linearity in the concentration range of 5-500 μg/mL was excellent （RE 〉 0.999）. The run-to-run repeatability （n = 3）, as expressed by the relative standard deviation （RSD） for migration times and peak areas were less than 0.5% and 3.0% respectively. The mean recovery ranged from 97.2% to 101.4%.

Detection of Catecholic Compounds with Field-ampilfied CZE-Amperometry

On-column sample stacking technique has been used extensively in capillary zone electrophoresis (CZE) to enhance the sensitivity of the measurements with UV-Vis detection. However, the detection limits for CZE-separation are still limit- ed due to the poor sensitivity of a UV-Vis detector. We incorporated field-amplified sample stacking technique into CZE with amperometric detection. Compared with the conventional electromigration injection , a negative peak of water was observed and a great enhancement of signals was obtained. The results in phosphate buffer with sodium dodecyl sulfate (SDS ) and 2-N-(morpholino) ethane sulphonic acid ( MES ) buffer were compared. Subnanomolar concentration limits for cate- cholamine neurotransmitters (dopamine, norepinephrine , epinephriine) and isopro- terenol were achieved in the 25 um capillary with two or three orders of magnitude lower than those with amperometric detection reported previously.

Simultaneous Determination of Catecholamines and Related Metabolites by Capillary Electrophoresis with Amperometric Detection

An electrophoretic method was developed for the determination of several important catecholamine markers, namely norepinephrine, epinephrine, dopamine, metanephrine, vanillylmandelic acid and homovanillic acid in urine samples. Under the optimum conditions, the six marker compounds could be well separated with the major coexisting interference compound uric acid within 24 rain at a separation voltage of 16 kV in a borate running buffer （80 mmol/L, pH=9.48）. Highly linear response can be obtained over three orders of magnitude for the above markers with the low limits of detection ranging from 1.0 ng/mL to 5.0 ng/mL（S/N=3）. The proposed capillary electrophoresis with amperometric detection（CE-AD） method has been used to simultaneously determine the six catecholamine markers in urine samples of healthy volunteers and patients suffering from different diseases avoiding redundant measurements and high assay cost; and the electrochemical profiles can suggest more diagnostic information of multiple diseases, which provides a promising and convenient entry into primary diagnoses of several clinical diseases.

Fast Determination of Clenbuterol and Salbutamol in Feed and Meat Products Based on Miniaturized Capillary Electrophoresis with Amperometric Detection

The fast separation capability of a novel miniaturized capillary electrophoresis with an amperometric detection （μCE-AD） system was demonstrated by determining clenbuterol and salbutamol in real samples. The effects of several factors such as the acidity and concentration of the running buffer, the separation voltage, the applied potential and the injection time on CE-AD were examined and optimized. Under the optimum conditions, the two β-agonists could be baseline separated within 60 s at a separation voltage of 2 kV in a 90 mmol/L H3BO3-Na2B4O7 running buffer （pH 7.4）, which was not interfered by ascorbic acid and uric acid. Highly linear response was obtained for above compounds over three orders of magnitude with detection limits ranging from 1.20×10^-7 to 6.50×10^-8 mol/L （S/N=3）. This method was successfully used in the analysis of feed and meat products with relatively simple extraction procedures.

Utilization of a platinum-modified carbon fiber electrode in capillary electrophoresis with amperometric detection

High performance capillary electrophoresis (HPCE) is a powerful tool for separation of complex compounds. Capillary electrophoresis with amperometric detection is a prospective research area in HPCE and has attracted wide attention because of its high sensitivity, small dead volume and inexpensive equipment. Only a few reports on the use of chemically modified electrode (CME) in capillary electrophoresis have been published. In this note a novel modified electrode dispersed with ultrafine platinum particles on the surface of a 30 7μm carbon fibre microelectrode

Fast Determination of Ethylendiamine in Aminophylline Tablets by Small-sized Capillary Electrophoresis with Amperometric Detection

A novel method for fast determination of ethylendiamine （EDA） in Aminophylline Tablets has been developed by small-sized capillary electrophoresis with amperometric detection （small-CE-AD） coupled with field-amplified sample injection （FASI）. Under the optimum conditions, EDA and four aliphatic diamine homologs （1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane and 1,6-diaminohexane） could be well separated within 6 min at a separation voltage of 2.0 kV in an acetate buffer solution of pH 3.8 with low limit of detection （LOD） of 1.3 × 10^-11 g/mL for EDA （S/N=3）. The proposed method has been successfully applied to direct deter- mination of EDA content in different batches of Aminophylline Tablets. The method does not require off-line preconcentration and derivatization steps, which should find wide application fields including pharmaceuticals as an alternative to conventional and microchip CE approaches.

乳制品中A1β-酪蛋白、A2β-酪蛋白检测方法研究进展

随着消费者对A2β-酪蛋白的关注度提升,A2β-酪蛋白相关产品不断更新换代。A2β-酪蛋白常用检测方法有反相高效液相色谱法(RP-HPLC)、液相色谱-高分辨串联质谱法、毛细管区带电泳法、试剂盒检测法等。本文对β-酪蛋白遗传变体A1β-酪蛋白和原始形态A2β-酪蛋白的功能特点、检测方法、定量分析进行综述,说明检测方法的原理和试剂药品的作用机理,加强对A1β-酪蛋白、A2β-酪蛋白检测方法的改进与优化,为A2β-酪蛋白应用于功能性食品、婴幼儿配方食品提供理论依据。

毛细管电泳法测定双氢青蒿素的含量

使用自行设计的毛细管电泳柱端安培检测系统,在乙醇为有机添加剂的条件测定了双氢青蒿素。研 究了工作电极、缓冲溶液浓度及其pH、有机溶剂的选择及其含量、检测电位和分离高压对测定的影响。结果 表明:选用Ag工作电极,检测电位为-0.6V,在20mmol/L硼砂,pH为9的运行介质的优化条件下,双氢青蒿 素在4min左右出峰,在1～200mg/L范围内,峰高与浓度呈良好的线性关系,检出限为0.05mg/L。

烟草中糖类物质的高效毛细管电泳-安培检测研究

将高效毛细管电泳－安培检测技术（ＨＰＣＥ－ＡＤ）用于不同烟草样品中糖类物质的测定。在 １×１０－６ｍｏｌ／Ｌ～１×１０－３ ｍｏｌ／Ｌ范围内，存在良好的线性关系，葡萄糖、果糖、蔗糖和麦牙糖的检测限均小于 ５．０ ×１０－７ｍｏｌ／Ｌ，结果令人满意。

毛细管电泳-安培检测法对甲基对硫磷、对硫磷、西维因和速灭威农药残留的测定研究

采用高效毛细管电泳 -安培检测法对农药甲基对硫磷、对硫磷、西维因和速灭威水解产物酚类进行了测定研究 ,考察了影响水解和毛细管分离的各种因素 :磷酸盐缓冲溶液的浓度、体系的 pH值、分离高压、检测电位等。结果表明 :在优化的实验条件下 ,标准样品15min内实现了基线分离 ,线性范围(mg/L) :间_甲酚、α_萘酚和对硝基苯酚均为0.05～10 ,信噪比为3时 ,测定检出限(mg/L) :间_甲酚0.04 ,α_萘酚0.02 ,对硝基苯酚0.03 ;对硫磷、速灭威和西维因回收率分别为91 % ,94%和101 % ,相对标准偏差分别为3.3 %、2.5 %和2.2 %(n=6)。