毛细管电泳-间接紫外检测法分离和测定食品中的有机酸

有机酸毛细管电泳（CE）分析是90年代初首先被报道的[1],近年来有了较大的发展[2]．采用CE法可进行不同基质样品如食品、饮料、尿液等样品中多种有机酸的同时分析[1,3,4]．该法采用CE的阴离子分离模式,在电解质溶液中加入电渗流改性剂,使电渗流方向逆向,从而与阴离子的电泳方向一致,以缩短分析时间．常见有机酸在200um以上大多无紫外吸收,一般采用间接紫外检测方法[1,3],也可采用低波长紫外检测[4]．低分子量阴离子的CE研究报道不多[5,6],有机酸的CE分离系统研究尚未见报道．本文系统地研究了毛细管电泳-间接紫外检测法分析…     

稀土离子及胺和氨基酸的高效毛细管区带电泳电导检测

用自制高效毛细管电泳装置研究毛细管电泳电导检测，由用阴离子交换膜管制作的导电接口连接电泳毛细管和电导池，高电压被有效隔离，实现柱后电导检测，用长６０ｃｍ、内径５０μｍ石英毛细管，以ｐＨ４．０的７×１０￣（－３）ｍｏｌ／ＬＮａＡｃ￣（－２）×１０￣（－３）ｍｏｌ／ＬＨＩＢＡ－ＨＡＣ溶液为载体，在１８ｋＶ电压下，轻重三种稀土Ｎｄ、Ｇｄ、Ｙｂ的混合物８ｍｉｎ内完成分离检测。用上述毛细管，以ｐＨ为５．８的５×１０￣（－３）ｍｏｌ／ＬＮａＡｃ－ＨＡＣ溶液为载体，在２０ｋＶ电压下乙二胺、三乙胺、组氨酸、谷氨酸混合有机物７．５ｍｉｎ内完成分离检测。     

毛细管电泳电化学发光检测体系中正高压进样条件下正负离子电场放大进样效应

毛细管电泳 (CE)正向着实际体系分析和微型化分析的方向发展[1,2 ] .为提高分离效率 ,CE的进样量一般很小 (1 0 - 12 ～ 1 0 - 9L ) ,因此常采用在线样品富集方式以提高检测灵敏度 .电场放大进样 (FASI)是 CE中实现在线样品富集的简便方式[3] ,随着 CE和检测技术的发展 ,其应用范围和研究体系不断扩大[4 ] .三联吡啶钌 [Ru(bpy) 2 + 3]电化学发光 (ECL )作为一种高灵敏、高选择性的检测方法被逐渐应用于 CE分析 (CE-ECL) .我们对这种技术进行了研究 ,并将其应用于临床分析[5～ 7] .实验中发现 ,在施加正高压的条件下 ,不同进样条…     

毛细管电泳无接触电导检测研究进展

毛细管电泳(CE)电导检测(CD)是相对较灵敏和仪器结构简单的一项溶液分析技术,尤其是对于无生色团的无机离子分析更具有突出优势,因此,CE-CD技术近年来得到了较快发展[1],并已推出商品化的毛细管电泳电导检测器[2]。但CE和CD的偶联目前还存在如下几个问题:第一,加工适合于毛细管     

腐蚀接头毛细管电泳电化学发光系统用于临床药物的快速检测

毛细管电泳作为近年来发展起来的分离分析技术,以其分辨率高、分离时间短及样品试剂用量小等特点而被广泛用于环境、生物以及临床分析^[1].基于三联吡啶钌的电化学发光检测技术结合了电化学检测的微型、原位和化学发光的高灵敏,可用于胺类、醇类、DNA以及免疫分析^[2].毛细管电泳和电化学发光检测技术的结合可以成为一种低费用、低成本及简便快速的分离分析技术.     

毛细管电泳在拮抗药物对氨基苯甲酸，对羟基苯甲酸和磺胺分析测…

本报道了一种用毛细管区带电泳法分离与测定对氨基苯甲酸、对羟基苯甲酸及磺胺类药物的新方法。电泳条件为：用２０ｍｍｏｌ／Ｌ硼砂－２０ｍｍｏｌ／ＬＨ３ＰＯ４－２０ｍｍｏｌ／Ｌβ－环糊精－４％乙醇作电泳液，Ｌ－抗坏血酸为内标，２８０ｎｍ为检测波长，样品由电进样方式１０ｋＶ／１０ｓ）引入毛细管（５１．２ｃｍ×５０μｍｉ．ｄ．，有效分离长度为３８．５ｃｍ）．在２４．５℃下，６ｍｉｎ内三可达基线分离（电泳电     

场放大样品进样-压力辅助毛细管区带电泳测定饮用水中的百草枯

1 引 言 百草枯属有机杂环类季铵盐除草剂,由于它具有优良的除草效果,已广泛应用于多种作物的杂草防治.百草枯具有极强的水溶性,极易迁移至水体环境中,从而对饮用水的质量安全构成潜在威胁.目前,百草枯的残留检测方法主要有分光光度法[1]、液相色谱-质谱联用法[2]、气相色谱质谱联用法[3]和毛细管电泳法(CE) [4～6].采用分光光度法测定百草枯,不仅操作繁琐费时,而且灵敏度低.采用气相色谱法测定百草枯,通常需要衍生化,应用较少[3].采用液相色谱法测定百草枯,通常需要在流动相中添加离子对试剂[2].毛细管电泳具有分离效率高,分析速度快等优点,已被广泛用于水样中百草枯残留的测定.然而,毛细管电泳灵敏度不高,极大地限制了其在实际样品分析中的应用.场放大样品进样(FASI)是一种简单有效的在线富集方法,其富集倍数可达1000倍[7],可有效提高毛细管电泳技术的灵敏度,因此应用较为广泛.本实验建立了场放大样品进样-压力辅助毛细管区带电泳法(CZE),用于测定饮用水中百草枯的残留量.     

毛细管等电聚焦-毛细管区带电泳二维蛋白质分离平台的构建及其性能

通常采用二维聚丙烯酰胺凝胶电泳 ( 2 D- PAGE)分析组织或细胞的全蛋白质 [1] ,但难与质谱 ( MS)直接联用 .用高效液相色谱 ( HPLC)和毛细管电泳 ( CE)分离分析蛋白质和多肽的一维分离模式的分辨率和峰容量有限 .多维柱联用技术比一维分离有更高的分辨率和峰容量 [2 ] ,便于和 MS直接联用 [3,4 ] ,易于实现自动化 .目前 ,有关 2 D- CE的报道相对较少 [5～ 7] ,我们初步实现了将 2 D- PAGE由平板转移到毛细管中[6 ,7] ,但凝胶柱的制作烦琐 ,存在交叉污染 ,不能与 MS直接联用 .本文用微透析中空纤维膜为接口构建了毛细管等电聚焦 ( …     

毛细管电泳-电感耦合等离子体质谱在痕量元素形态分析中的应用

叙述了元素形态分析的目的和意义以及发展概况，并在此基础上着重叙述了近年来毛细管电泳(CE)与电感耦合等离子体质谱(ICP-MS)联用技术在痕量元素形态分析上的应用，包括该联用技术的关键CE与ICP-MS接口的不同设计，影响CE分离分辨率及分析灵敏度的主要因素。对这种分析技术在元素形态分析上应用的潜力和限制以及发展趋势作了讨论。     

缺口型试样管阵列进样系统与紫外检测毛细管电泳联用技术

将基于缺口型试样管阵列的微流控试样引入系统与紫外检测-毛细管电泳系统联用，建立可实现自动化、高通量、连续试样引入的微型化毛细管电泳系统。试样引入系统由底部加工有缺口的试样管阵列构成，阵列固定于一维平移台上。实验时，通过平移试样管阵列，使毛细管和电极依次经缺口进入装有试样或缓冲液的试样管内，完成电动进样和电泳分离操作。该系统被用来快速分离复方新诺明片中的磺胺甲嗯唑（SMZ）和甲氧苄氨嘧啶（TMP），以考察系统分析性能。分析通量达到72样／h，试样间携出量为1．4％，对SMZ的分离塔板高度11μm。采用紫外检测对SMZ和TMP检出限（3σ）分别为9．8mg／L和12．2mg／L。     

Interface for capillary electrophoresis coupled with inductively coupled plasma atomic emission spectrometry.

A modified concentric nebulizer was used as the interface to couple capillary electrophoresis (CE) to inductively coupled plasma atomic emission spectrometry (ICP-AES). The CE capillary replaces the central tube of the concentric nebulizer. The tip of the nebulizer tapers slowly to allow uncertainty in the position of the capillary. A platinum wire was inserted into the CE capillary to provide electrical connection to the CE power supply. pH changes inside the capillary due to electrolysis of the background buffer electrolyte was small and has minimal effects on the CE separation. The peak broadening effects due to the nebulizing gas flow, however, were significant. Resolution decreases quickly when the flow-rate of the carrier gas increases. Sample stacking technique was used to improve the resolution of species of opposite charge, e.g., Cr(VI) vs. Cr(III) ions. Detection limit of Cr based on peak area is approximately 10 ppb for the CE-ICP-AES system.     

Simple interface for capillary electrophoresis-inductively coupled plasma atomic emission spectrometry

A simple interface has been developed to couple capillary electrophoresis (CE) to inductively coupled plasma atomic emission spectrometry (ICP-AES) for metal speciation. A concentric glass nebulizer with elongated tip is used as the CE-ICP interface. The CE capillary is the central tube of the nebulizer. A platinum wire is wrapped across the exit end of the CE capillary to provide electrical connection to the CE power supply. No sheath flow of buffer solution is needed. A simple cooling system has also been developed. A peristaltic pump circulates water through a plastic tube that encloses the section of the CE capillary between the CE instrument and the ICP spectrometer. Characteristics of the CE-ICP interface, e.g., elution time, nebulization and transport efficiency and peak broadening, versus carrier gas flow-rate have been studied. Comparisons to a previous design with the Pt electrode inserted into the end of the CE capillary are made where appropriate. The reproducibility (RSD) in ICP emission intensity of the system is <4%. Detection limits of Cr and Cu are approximately 5 ng/ml.     

Metal speciation using capillary electrophoresis--inductively coupled plasma atomic emission spectrometry and polytetrafluoroethylene capillaries

A capillary electrophoresis--inductively coupled plasma atomic-emission spectrometry (CE-ICP-AES) system using a polytetrafluoroethylene (PTFE) capillary has been developed. The CE-ICP interface was a modified concentric nebulizer. The PTFE capillary (50 microm internal diameter) was used as the central capillary of the nebulizer. Using the PTFE capillaries, the solution flow rate induced by the carrier gas flow was smaller than that of glass capillary. Solution flow was mainly induced by the CE electric field. Baseline separation of Ba2+/Mg2+ ion pair using simple buffer solution of 0.014 M sodium acetate was reported. Separation and correlation of metal species in metallothioneins (MT-1 and MT-2 in MT) of rabbit liver using the CE-ICP system were also discussed.     

Optimization of the hyphenation between capillary zone electrophoresis and inductively coupled plasma mass spectrometry for the measurement of As-, Sb-, Se- and Te-species,applicable to soil extracts

The optimization of the hyphenation between capillary zone electrophoresis (CZE) and inductively coupled plasma mass spectrometry (ICP-MS) was studied for the simultaneous determination of metalloid species in the environment. Arsenic (arsenite, arsenate, monomethylarsonic acid, dimethylarsinic acid), selenium (selenite, selenate, selenomethionine, selenocystine), antimony (antimonate) and tellurium (tellurite, tellurate) species were simultaneously separated using a 75-μm i.d. fused silica capillary using either a chromate or a phosphate electrolyte. Different nebulizers were tested for introduction in the detector. A V-groove nebulizer (the Babington) and two concentric micronebulizers (the MCN-100 and the MicroMist) were studied in order to improve resolution, sensitivity and reproducibility. The optimization of CE-ICP-MS interface operating parameters is discussed for each nebulizer–interface combination, and special attention is given to the position of the capillary inside the nebulizer. Different nebulizer gas and liquid sheath flow rates were studied in detail and they hardly affect electrophoretic resolution and peak width. The best analytical performance characteristics were obtained with the MicroMist nebulizer. Detection limits with this nebulizer were found to range between 6 and 58 μg l⁻¹ depending on the species investigated using pressure injection and below 1 μg l⁻¹ for most of the species with electromigrative injection. Analysis of soil extracts showed that it was possible to carry out this technique on real samples.     

Use of factorial design for evaluation of plasma conditions and comparison of two liquid sample introduction systems for an axially viewed inductively coupled plasma optical emission spectrometer

A factorial design was applied to evaluate plasma conditions employing the Mg II 280/Mg I 285 nm intensity ratio in an axially viewed inductively coupled plasma optical emission spectrometer using different sample introduction devices: a concentric or a V-groove nebulizer and a cyclonic or a Sturman-Masters spray chamber. Effects of nebulizer gas flow-rate on Mg II/Mg I ratio were different in each introduction system. Robust conditions were obtained at low nebulizer gas flow-rate when using concentric nebulizer with a cyclonic spray chamber or a concentric nebulizer and a Sturman-Masters spray chamber. However, when using a V-groove nebulizer with a Sturman-Masters spray chamber, Mg II/Mg I ratio increased at high nebulizer gas flow-rates. Recovery experiments for a milk standard reference material diluted in water-soluble tertiary amines in both robust and non-robust conditions indicated that the robust condition was reached at higher nebulizer gas flow-rates and led to better accuracy and precision when using a V-groove nebulizer.     

氢化物发生-电感耦合等离子体质谱联用技术研究

运用自制的接口，实现了氢化物发生与电感耦合等离子体质谱的联用。考察了连续流动氢化物发生器、气动型断流式氢化物发生器及气动型流动注射氢化物发生器与电感耦合等离子体质谱仪的联用性能。确定了仪器的最佳参数，研究了系统的分析性能，实现了能生成氢化物的8种元素的定量测定。     

Modified Babington nebulizer for inductively coupled plasma atomic emission spectrometry.

A PTFE Babingtonnebulizer equipped with a hood was investigated for inductively coupled plasma atomicemission spectrometry in conjunction with a PTFE cyclone chamber, in order to nebulize various sample solutions containing high salts, hydrofluoric acid and/or suspended solid. A hood of 3 mmphi (nozzle side) - 5 mmphi (outlet side) and 6 mm in length gave a comparable or higher sensitivity compared to a system with a commercially available concentric nebulizer and a glass cyclone chamber. Moreover, the present nebulizer was fully interchangeable with a concentric one at normal argon pressure, attaining sufficient stability, a short wash-out time and good nebulizing of high matrices solutions. The present system was successfully applied to the determination of trace impurities in highly pure silica powders.     

Simultaneous electrothermal vaporization and nebulizer sample introduction system for inductively coupled plasma mass spectrometry

The novel analytical application of the combination of an inline electrothermal vaporization (ETV) and nebulization source for inductively coupled plasma mass spectrometry (ICP-MS) has been studied. Wet plasma conditions are sustained during ETV introduction by 200 mL/min gas flow through the nebulizer, which is merged with the ETV transport line at the torch. The use of a wet plasma with ETV introduction avoided the need to change power settings and torch positions that normally accompany a change from wet to dry plasma operating conditions. This inline-ETV source is shown to have good detection limits for a variety of elements in both HNO₃ and HCl matrices. Using the inline-ETV source, improved limits of detection (LOD) were obtained for elements typically suppressed by polyatomic interferences using a nebulizer. Specifically, improved LODs for ⁵¹V and ⁵³Cr suffering from Cl interferences (⁵¹ClO⁺ and ⁵³ClO⁺ respectively) in a 1% HCl matrix were obtained using the inline-ETV source. LODs were improved by factors of 65 and 22 for ⁵¹V and ⁵³Cr, respectively, using the inline-ETV source compared to a conventional concentric glass nebulizer. For elements without polyatomic interferences, LODs from the inline-ETV were comparable to conventional dry plasma ETV-ICP time-of-flight mass spectrometry results. Lastly, the inline-ETV source offers a simple means of changing from nebulizer introduction to inline-ETV introduction without extinguishing the plasma. This permits, for example, the use of the time-resolved ETV-ICP-MS signals to distinguish between an analyte ion and polyatomic isobar.     

A Modification of the Concentric Glass Nebulizer for Analyzing High Salt Content Samples

The present paper introduces a new type of concentric glass nebulizer named "LB-II nebulizer". It is the modification between the LB nebulizer (1) and the Meinhard. Its out face is similar with the Meinhard, but the LB-11 nebulizer is capable of continuous operation with saturated solutions of NaCl (26.54% at 25° C) for more than 2 hours without clogging, and the stability is superior than the LB nebulizer. The argon air flowing remains constantly during the operation. Its structure is very simple in nebulizers to analysis high salt solutions by using the ICP-AES. The operating conditions are same for these two nebulizers and the results between them are shown in the table. The LB-II nebulizer can give higher signal-to-background ratios and lower detection limits than the Meinhard neblizer as shown in the table.     

A study of designs of a cross flow nebulizer for ICP atomic emission spectrometry

Effects of some design parameters of a cross flow nebulizer on nebulization characteristics are described. The performance in ICP work is compared with that of a commercially available concentric nebulizer.