毛细管区带电泳同时测定化妆品中的阴阳离子

Natural Sea Beauty系列化妆品富含来自Dead Sea水中的矿物质,对皮肤有较好的治疗和滋养作用.本文采用毛细管区带电泳的技术,电迁移双端进样,5 mmol/L咪唑-2 mmol/L硝酸为背景电解质,以富马酸调至pH 4.1,UV间接测定法(214nm),在6min内同时检测了化妆品中的阴阳离子(K⁺、Na⁺、Ca²⁺、Mg²⁺、Cl^-、Br^-),与离子色谱法所得结果进行了对照.此方法可为鉴别不同品牌的化妆品提供一定的依据.     

Determination of Amino Acids in Panax notoginseng by Microwave Hydrolysis and Derivatization Coupled with Capillary Zone Electrophoresis Detection

The microwave hydrolysis and derivatization coupled with capillary electrophoresis detection were developed for the separation and determination of the amino acids in Panax notoginseng.The experimental conditions for the microwave hydrolysis and derivatization were examined and optimized. Several parameters of capillary electrophoresis, such as pH value of background electrolyte, borate concentration and applied voltage were optimized. Under the selected conditions, 11 amino acids were completely separated. The real sample was analyzed and the results were satisfactory. Compared with that of conventional heat hydrolysis and derivatization, the analytical time of this method was significantly shortened.     

Rapid determination of short chain carnitines in human plasma by electrospray ionisation-ion trap mass spectrometry using capillary electrophoresis instrument as sampler

A capillary electrophoresis apparatus was used as sampler for flow injection analysis (FIA) in tandem mass spectrometry of L-carnitine and its acetyl- and propionyl-metabolites in human plasma. The capillary electrophoresis instrument was coupled to the ion trap mass spectrometer by an electrospray ionization coaxial sheath liquid interface. The electrophoresis capillary introduced the sample directly into the source by applying a prolonged sample injection. The use of the capillary electrophoresis apparatus miniaturised the FIA procedure, substantially reducing the quantities of solvents and samples used, and allowed rapid automated sequential analyses. The method was optimised and validated using a dialyzed human plasma matrix. The plasma samples were analysed after a simple, rapid deproteinisation procedure with acetonitrile and diluted 70 times before direct injection into the mass spectrometer for product ion scan MS/MS analysis in positive ionisation. The total analysis time was 5 min, including capillary preconditioning and acquisition time (3 min). The method was sensitive, allowing the determination of L-, L-acetyl- and L-propionyl-carnitines at 140, 14 and 3.6 nM concentrations (injected values) corresponding to lower limit of quantitation values in plasma of 10, 1 and 0.25 microM, respectively. The method was processed for full validation and applied to the analysis of L-carnitine and its short chain derivatives in human plasma samples.     

食品中金属离子的微波消解-高效毛细管电泳法测定

采用微波消解－高效毛细管电泳法测定食品中的K，Na,Ca,Mg等金属离子，考察了微波消解的最佳条件；研究了背景电解质，缓冲液pH值，操作温度和分离电压等对电泳分离中运行电流，电渗迁移率，峰形等参数的影响，确定了金属离子电泳分离的最佳实验条件；该法已应用于食品中金属离子的测定，并与原子吸收法进行比较，得到满意的结果。     

Simultaneous analysis of Cu and Pb as ABEDTA complexes in Rhizoma coptidis by capillary electrophoresis coupled with solid phase extraction

A novel capillary electrophoresis method for simultaneous determination of Cu and Pb has been developed in this paper.Cu（Ⅱ） and Pb（Ⅱ） ions were reacted with ABEDTA to form complex to achieve an ideal sensitivity of heavy metal complexes.The digestion solution of Rhizoma coptidis drug sample was purified by neutral Al₂O₃ column chromatography and the chromatographic behavior of metal-L complexes was investigated.The calibration curve was linear in the range of 5-60μg/mL for Cu²⁺ and 5-25μg/mL for Pb²⁺ with the correlation coefficients 0.9970 and 0.9972 for each（n = 5）.The average recoveries were 86.2%for Pb and 90.1%for Cu,while the relative standard deviations were 5.1%and 3.6%respectively.The method was successfully applied to determine Cu and Pb in R.coptidis drug samples.     

湿法快速消解-原子荧光光谱法测定农产品中汞含量

建立了湿法快速消解-原子荧光光谱仪测定农产品中汞含量的方法。选取大米和芹菜作为实验样品,对消解酸体系(硝酸、硝酸-过氧化氢、硝酸-高氯酸)、消解温度(100、110、120、130、140℃)和消解时间(30、45、60、90 min)等条件进行探讨,确定最佳实验条件,并与常规微波消解效果进行对比。结果表明,优化后的硝酸-高氯酸体系条件下120℃消解30 min,方法在0~2μg/L范围内线性关系良好,相关系数为0.9996,方法检出限为0.001 mg/kg,精密度为2.4%~3.9%。两种消解方法对于大米和芹菜质控样的测定值基本一致,均在质控样范围。相较于常规微波前处理方法,简化了样品前处理流程,提高了工作效率,可为农产品汞含量检测提供可靠的方法支撑。     

Trypsin entrapped in poly(diallyldimethylammonium chloride) silica sol-gel microreactor coupled to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

An enzyme-immobilized capillary microreactor for rapid protein digestion and proteomics analysis is reported. The inner surface of the fused-silica capillary was coated with poly(diallyldimethylammonium chloride) (PDDA)-entrapped silica sol-gel matrix, followed by assembly of trypsin onto the PDDA-modified surface via electrostatic adsorption. The immobilization parameters such as PDDA content in the sol-gel matrix, trypsin concentration and pH were investigated in detail. Protein samples including beta-casein, myoglobin and cytochrome c could be effectively digested and electrophoretically separated simultaneously in such a modified capillary. Just 2.26 ng (corresponding to 0.10-0.14 picomole) of sample was sufficient for on-line capillary electrophoresis peptide mapping. The efficiency of the digestion was further demonstrated by digestion of a human liver cytoplasm sample and 253 proteins were identified in one unique run.     

Rapid and cost‐effective method for the simultaneous quantification of seven alkaloids in Corydalis decumbens by microwave‐assisted extraction and capillary electrophoresis

A rapid and cost‐effective method based on microwave‐assisted extraction followed by capillary electrophoresis was developed for simultaneous quantification of seven alkaloids in Corydalis decumbens for the first time. The main parameters affecting microwave‐assisted extraction and capillary electrophoresis separation were investigated and optimized. The optimal microwave‐assisted extraction was performed at 40°C for 5 min using methanol/water (90:10, v/v) as the extracting solvent. Electrophoretic separation was achieved within 15 min using an uncoated fused‐silica capillary (50 μm internal diameter and 27.7 cm effective length) and a 500 mM Tris buffer containing 45% v/v methanol (titrated to pH^* 2.86 with H₃PO₄). The developed method was successfully applied to the quantification of seven alkaloids in Corydalis decumbens obtained from different regions of China. The combination of microwave‐assisted extraction with capillary electrophoresis was an effective method for the rapid analysis of the alkaloids in Corydalis decumbens .     

A rapid and simple microwave-assisted digestion procedure for spectrophotometric determination of titanium dioxide photocatalyst on activated carbon

Deposition of titanium dioxide (TiO₂) on activated carbon (AC) surface has been widely utilized for the production of TiO₂/AC photocatalyst, which can be used in photo-degradation of pollutants. In this work, a fast and simple digestion procedure has been developed for the spectrophotometric quantitative analysis of TiO₂ in TiO₂/AC photocatalyst. Microwave-assisted digestion was used in the procedure. The microwave-digestion procedure was optimized using the single-variable method. Variables optimized included time of ashing, effective digestion time, volume and concentration of sulfuric acid, effect of adding a digestion catalyst, effect of sample pulverizing and on–off time cycle of the microwave. The analysis was completed spectrophotometrically after addition of hydrogen peroxide to the digested solution. Procedure precision and accuracy was tested by application to photocatalyst samples containing known amounts of TiO₂, and compared with previously published spectrophotometric procedures. The proposed microwave procedure was capable of recovering 98.4–101.1% of TiO₂ in the catalyst in less than 10 min, without the need for sample ashing. Analytical precision is 1.42–2.39% relative standard deviation (R.S.D.). In terms of accuracy and precision, the proposed microwave procedure was comparable with other procedures, but the proposed microwave procedure was superior in terms of shorter procedure duration.     

Development and validation of a capillary electrophoresis method for the characterization of sulfoethyl cellulose

To characterize sulfoethyl cellulose el samples, a capillary electrophoresis method was developed and validated sulfoethyl cellulose el was hydrolyzed, and the resulting d ‐glucose derivatives were analyzed after reductive amination with 4‐aminobenzoic acid using 150 mM boric acid, pH 9.5, as background electrolyte at 20°C and a voltage of 28 kV. Peak identification was derived from capillary electrophoresis with mass spectrometry using 25 mM ammonia adjusted to pH 6.2 by acetic acid as electrolyte. Besides mono‐, di‐, and trisulfoethyl d ‐glucose small amounts of disaccharides could be identified resulting from incomplete hydrolysis. The linearity of the borate buffer‐based capillary electrophoresis method was evaluated using d ‐glucose in the concentration range of 3.9–97.5 μg/mL, while limits of detection and quantification derived from the signal‐to‐noise ratio of 3 and 10 were 0.4 ± 0.1 and 1.2 ± 0.3 μg/mL, respectively. Reproducibility and intermediate precision were determined using a hydrolyzed sulfoethyl cellulose el sample and ranged between 0.2 and 8.8% for migration times and between 0.3 and 10.4% for peak area. The method was applied to the analysis of the degree of substitution of synthetic sulfoethyl cellulose el samples obtained by variation of the synthetic process and compared to data obtained by elemental analysis.     

毛细管区带电泳法间接测定红细胞中的主要无机阳离子

建立了间接测定红细胞中主要无机阳离子的毛细管区带电泳方法, 考察了背景溶液pH、咪唑和酒石酸浓度等对无机离子分离效果及峰面积的影响. 以10 mmol/L咪唑-4 mmol/L酒石酸(pH 5.5)为背景, 在15 kV、214 nm的条件下, 对红细胞中K 、Mg2 、Ca2 和Zn2 进行了定性、定量分析, 回收率在96%～104%之间, 迁移时间和峰面积的相对标准偏差分别低于0.76%和2.8%(日内), 0.85%和3.7%(日间). 所建方法有望成为一种测定细胞内离子含量的辅助方法.     

Multi-syringe flow injection system with in-line microwave digestion for the determination of phosphorus

A multi-syringe system for spectrophotometric determination of total phosphorus involving in-line digestion is proposed. Sample and digestion solution were dispensed and directed towards a digestion vessel located inside a domestic microwave oven (MWO) where sample digestion took place. Afterwards, the digested sample was merged with the necessary reagents for the colorimetric determination based on the molybdenum blue method. Several digestion conditions were studied regarding composition of digestion solution, digestion time and power set on the MWO. The system was applied to waste water samples and results shown a good agreement with the reference method. Repeatable results (R.S.D.<2.41%) and determination frequency of 12 h⁻¹ were obtained.     

Automatic flow-injection system for the determination of heavy metals in sewage sludge by microwave digestion and detection by inductively coupled plasma-atomic emission spectrometry (MW-ICP/AES)

Results are shown obtained in the optimization of an automatic flow injection system that combines microwave digestion with atomic spectrometric detection (FAAS, ICP/AES) for the determination of heavy metals in sewage sludge. Digestion is performed by preparing a suspension of the sample in 1.5 mol/l HNO(3) and making it flow through a PTFE capillary tube placed inside a conventional microwave oven. The effects of the length and inner diameter of the capillary tube, as well as that of the pumping rate, have been studied in order to find the experimental conditions that allow a quantitative elemental recovery in the shortest period of time possible. The optimization study was carried out on a certified sample (BCR No. 146), and the elements determined were Zn, Cu, Pb, Cd, Ni and Cr. The experimental data (percent recovery vs. digestion time) have been fitted to a mathematical model in order to quantify the influence of each of the variables studied. The optimized procedure (MW-ICP/AES) has been applied to one ordinary and one certified sewage sludge sample. In comparison with the conventional methods of sewage sludge analysis, the one proposed is less time consuming, while being equally precise and accurate.     

Gene analysis of multiple oral bacteria by the polymerase chain reaction coupled with capillary polymer electrophoresis

Capillary polymer electrophoresis is identified as a promising technology for the analysis of DNA from bacteria, virus and cell samples. In this paper, we propose an innovative capillary polymer electrophoresis protocol for the quantification of polymerase chain reaction products. The internal standard method was modified and applied to capillary polymer electrophoresis. The precision of our modified internal standard protocol was evaluated by measuring the relative standard deviation of intermediate capillary polymer electrophoresis experiments. Results showed that the relative standard deviation was reduced from 12.4–15.1 to 0.6–2.3%. Linear regression tests were also implemented to validate our protocol. The modified internal standard method showed good linearity and robust properties. Finally, the ease of our method was illustrated by analyzing a real clinical oral sample using a one‐run capillary polymer electrophoresis experiment.     

Effect of NaOH on large-volume sample stacking of haloacetic acids in capillary zone electrophoresis with a low-pH buffer

Large-volume sample stacking (LVSS) is an effective on-capillary sample concentration method in capillary zone electrophoresis, which can be applied to the sample in a low-conductivity matrix. NaOH solution is commonly used to back-extract acidic compounds from organic solvent in sample pretreatment. The effect of NaOH as sample matrix on LVSS of haloacetic acids was investigated in this study. It was found that the presence of NaOH in sample did not compromise, but rather help the sample stacking performance if a low pH background electrolyte (BGE) was used. The sensitivity enhancement factor was higher than the case when sample was dissolved in pure water or diluted BGE. Compared with conventional injection (0.4% capillary volume), 97-120-fold sensitivity enhancement in terms of peak height was obtained without deterioration of separation with an injection amount equal to 20% of the capillary volume. This method was applied to determine haloacetic acids in tap water by combination with liquid-liquid extraction and back-extraction into NaOH solution. Limits of detection at sub-ppb levels were obtained for real samples with direct UV detection.     

Determination of inorganic cations by capillary ion electrophoresis in Ilex paraguariensis (St. H.), a plant used to prepare tea in South America

A practical and economical capillary ion electrophoresis method with indirect UV detection at 214 nm was developed for determination of inorganic cations in plants of Ilex paraguariensis(St. H.) and their infusion known as mate tea, a very popular beverage in South America. A microwave digestion procedure was used to prepare the herbal plants, but the infusion was only diluted. The background electrolyte contained 6mM imidazole and 10mM alpha-hydroxyisobutyric acid, pH 4.0. The running voltage was 20 kV and temperature was 25 degrees C. K, Na, Ca, Mg, and Mn ions were quantitated, and linearity was demonstrated between 0.6 and 120 ppm. The results were in good agreement with those obtained by flame atomic absorption and emission spectrometry. Accuracy of the method was verified by comparison with Beech leaves CRM 100, a standard reference material. The high content of minerals and several oligoelements, especially Mn in mate tea, is considered to be of nutritional interest.     

单链构象多态性-毛细管电泳分析中样品纯化研究

聚合酶链反应(PCR)样品中的Cl^-、引物等小分子对单链构象多态性一毛细管电泳分析有重要影响。本文用毛细管电泳一间接紫外法测定了PCR样品中的Cl^-浓度,并对乙醇沉淀法和试剂盒纯化法用于PCR样品的纯化效果进行比较,在此基础上研究了Cl^-浓度、引物及其二聚体在SSCP-CE分析中的影响。结果表明,它们主要影响DNA进样量而对分离效率影响不大。     

Automatic flow-injection system for the determination of heavy metals in sewage sludge by microwave digestion and detection by inductively coupled plasma-atomic emission spectrometry (MW-ICP/AES)

Results are shown obtained in the optimization of an automatic flow injection system that combines microwave digestion with atomic spectrometric detection (FAAS, ICP/AES) for the determination of heavy metals in sewage sludge. Digestion is performed by preparing a suspension of the sample in 1.5 mol/l HNO₃ and making it flow through a PTFE capillary tube placed inside a conventional microwave oven. The effects of the length and inner diameter of the capillary tube, as well as that of the pumping rate, have been studied in order to find the experimental conditions that allow a quantitative elemental recovery in the shortest period of time possible. The optimization study was carried out on a certified sample (BCR No. 146), and the elements determined were Zn, Cu, Pb, Cd, Ni and Cr. The experimental data (percent recovery vs. digestion time) have been fitted to a mathematical model in order to quantify the influence of each of the variables studied. The optimized procedure (MW-ICP/AES) has been applied to one ordinary and one certified sewage sludge sample. In comparison with the conventional methods of sewage sludge analysis, the one proposed is less time consuming, while being equally precise and accurate.     

肉类制品中微量锶的分离及^87Sr/^86Sr同位素比值测定

利用87Sr/86Sr同位素比值进行生物和古人类源区与迁徙的示踪是Sr同位素技术应用的新领域,也是考古研究和肉类食品溯源研究的新尝试。本研究对牛肉干粉采用酸溶、微波消解和灰化后硝酸提取等不同方法进行消解,比较了它们的离子交换分离效果和Sr同位素测定结果;用石英、石墨和瓷坩埚3种器皿对牛肉干粉进行灰化,检测了灰化器皿对87Sr/86Sr同位素比值的影响,从而确定了石英坩埚灰化的消解方法,建立了适合于肉类制品微量Sr的化学分离方法与87Sr/86Sr同位素比值测定方法。本方法包括肉类制品的石英坩埚灰化、离子交换分离和87Sr/86Sr比值的热离子化质谱测定。所建方法对肉类食品溯源和考古研究等领域富含有机质样品的Sr同位素比值测定具有普适性。     

Combining capillary electrophoresis with mass spectrometry for applications in proteomics

Mass spectrometry (MS)-based proteomics is currently dominated by the analysis of peptides originating either from digestion of proteins separated by two-dimensional gel electrophoresis (2-DE) or from global digestion; the simple peptide mixtures obtained from digestion of gel-separated proteins do not usually require further separation, while the complex peptide mixtures obtained by global digestion are most frequently separated by chromatographic techniques. Capillary electrophoresis (CE) provides alternatives to 2-DE for protein separation and alternatives to chromatography for peptide separation. This review attempts to elucidate how the most promising CE modes, capillary zone electrophoresis (CZE) and capillary isoelectric focusing (CIEF), might best be applied to MS-based proteomics. CE-MS interfacing, mass analyzer performance, column coating to minimize analyte adsorption, and sample stacking for CZE are considered prior to examining numerous applications. Finally, multidimensional systems that incorporate CE techniques are examined; CZE often finds use as a fast, final dimension before ionization for MS, while CIEF, being an equilibrium technique, is well-suited to being the first dimension in automated fractionation systems.