窄内径多孔层开管柱的制备及在液相色谱中的应用

近年来,微纳分离技术由于其内在的优势而受到越来越多的关注.多孔层开管柱是一种重要的微分离柱形式,与粗内径的多孔层开管柱(>25μm)相比,窄内径的多孔层开管柱具有更高的分离效率和更低的试剂消耗量.本文综述了内径≤25μm的窄内径多孔层开管毛细管柱的制备方法、与质谱检测联用技术以及在液相色谱中的应用研究进展,对其发展前景进行了展望.     

色谱法中的谱带和色谱峰

对色谱法中的谱带作了具体的定义。详细论述了谱带与色谱峰之间的关系,指出分析谱带是研究色谱现象的基础。色谱法中的色谱峰并不局限于色谱图中的色谱峰,只要是组分的分析谱带,都可以形成一个色谱峰与之相对应。     

氧化苦参碱、槐定碱和苦参碱在离子交换色谱上的色谱行为研究

采用离子交换色谱法,以氧化苦参碱、槐定碱、苦参碱3种生物碱为对象,研究了流动相pH、缓冲液浓度及三乙胺加入量等色谱条件对生物碱色谱行为的影响,并探讨了其作用机制。结果表明：流动相pH对生物碱的色谱保留行为影响显著,流动相pH接近生物碱pKa时,3种生物碱的保留值迅速降低,生物碱pKa值可用于指导流动相pH的选择;在缓冲液浓度为20～100mmol／L范围内,随着缓冲液浓度增加,生物碱的保留值逐渐减小、柱效有所增加;流动相中三乙胺的加入对生物碱的保留值、对称性及柱效均有一定影响,可达到掩蔽游离硅羟基的作用。将该方法用于苦参药材中3种生物碱的分离检测。     

低酸度淋洗液离子色谱法测定多聚磷酸盐

在国产阴离子分离柱上采用含钙和镁离子的淋洗液，由于Ｃａ＾２＋和Ｍｇ＾２＋与复杂的多聚磷酸根离子形成螯合物而提高了淋洗能力，加快了分析速度，大大降低了淋洗液的酸度和盐浓度，对几种工业三聚磷酸钠样品进行了测定，与化学法相比，相对误差小于１．５％，加入回收率在９９％－１０９％之间。     

Metal Ion Chromatography with Fluorescence Detection

Abstract

Nonpolar, agglomerated anion exchanger, and surface-sulfonated cation exchanger stationary phases have been used in conjunction with 8-hydroxyquinoline-5-sulfonic acid (HQS) in the eluent or as a postcolumn reagent for the separation and detection of a number of metals that form fluorescent HQS complexes. Several metals, notably those classified as transition metals, form nonfluorescent HQS chelates and quenches the fluorescence of other metal-HQS metal chelates. Such transition metals have been detected by introducing the fluorescent Al-HQS chelate postcolumn. Cation exchange stationary phases are the most useful for chromatographic applications involving HQS and are able to provide a variety of useful separations by tailoring elution conditions. Although not sensitive to Ba, the approach may be particularly good for the determination of the other alkaline earth metals. Fluorescence quenching resulting from Fe and Ni leaching from stainless steel chromatographic systems present a problem for trace analysis and accentuate the need for nonmetallic hardware. Subpicomole detection limits are attainable for Cd, Mg and Zn.     

螯合物离子色谱

螯合物离子色谱是一种利用螯合物进行不同方式分离和检测的离子色谱模式，目前已经被痕量金属分析广泛采用，本文对一些螯合物阳离子交换色谱、螯合物色谱、阴离子交换色谱和离子对色谱最新进展进行了综述，并采用基本螯合物化学理论（金属螯合物稳定性、金属原子有效电荷、螯合剂能力等）对保留和分离机理进行了讨论。     

大孔径毛细管气相色谱法快速测定饮料中的氯胺酮

采用固相萃取技术 ,以二十二烷为内标 ,FID检测器 ,建立了一种测定饮料中的氯胺酮的大孔径毛细管气相色谱新方法 .测定结果表明氯胺酮的线性范围为 0 0 2mg/L - 6 4mg/L ,其最低检测浓度为 0 0 2mg/L ,相对标准偏差为 2 6 % ,平均回收率为 85 6 % .该法简便 ,准确 ,重现性好 ,结果令人满意     

Ion Exchange Capacity of Chromatographic Paper

Abstract

The ion exchange capacities of Whatman No. 1 and Whatman CM81 chromatographic papers, with and without pre-washing, were determined chromatographically using lead nitrate and lead chloride. Mean values with standard deviations are reported. Statistical analysis indicates that pre-washing with acetic acid, perchloric acid, and disodium dihydrogen ethylene, diaminetetraacetate affects the capacity by the same amount at the 95% confidence limit.     

Ion Chromatographic Determination of Sodium Isethionate

Abstract

Single column anion chromatography with conductivity detection has been used for the determination of sodium isethionate. A mobile phase of aqueous phthalic acid - methanol (pH 2.5) allows for the separation of isethionate from chloride and alkyl isethionate ester surfactants. Commercially available samples of sodium isethionate and alkyl esters were analyzed by the described procedure.     

宽口径填充毛细管液相色谱柱柱尾结构的改进

 设计并评价了尾锥形填充毛细管液相色谱柱,与粘结型柱尾比较,前者柱效高且van Deemter曲线高流速部分的流速-柱效关系明显改善。在折合流速为10～15时,前者的柱效比后者高出30%～50%。谱带的抛物线状的流形在尾锥形柱内得到改善,使色谱峰的对称性有明显提高。比较了两种结构的色谱柱在芳烃快速分析中的分离效果,结果是尾锥形柱的分离性能优于粘结型柱。     

A Novel Neutral Carrier for Uranyl Ion Based on a Commercially Available Aminophosphate Derivative: Evaluation in Membrane Electrodes and Nuclear Safeguards Applications

The construction and performance characteristics of uranyl membrane electrodes based on cheap and commercially available amino(trimethyl)phosphate are described. The influence of various membrane constituents on the potentiometric responses of the prepared membrane electrodes has been studied. Optimized membrane electrodes exhibited performance characteristics comparable with those based on high cost and commercially available ionophores. Selectivity studies indicated that the developed membrane electrodes are selective towards uranyl ion over a large number of cations including the well‐known uranyl ion interferents (e.g., Fe³⁺, Th⁺⁴). The analytical utility of the proposed membrane electrode has been demonstrated through its application in nuclear safeguards verification purposes.     

手性离子对色谱法

阐述了手性离子对色谱分离药物对映体的基本原理。在ＨＰＬＣ流动相中加入光学纯反离子可与流动相中的对映体生成非对映体复合物（离子对）,离子对复合物之间具有不同的稳定性和分配性质,并可与固定相发生不同的静电、疏水和氢键作用,进而差速迁移得以分离。影响方法立体选择性的主要因素有：反离子的性质（酸碱性、亲脂性、光学纯度）、反离子的浓度、流动相的组分、流动相的流速、固定相的性质和色谱柱的温度等。     

8种农药的大口径毛细管气相色谱分析

1　引　　言2 0世纪 80年代 ,毛细管气相色谱 (CGC)技术就广泛用于农药残留分析。现在毛细管气相色谱与固相萃取、固相微萃取、质谱等技术一起 ,被广泛地应用于农药的多残留分析。但作为农药原药和制剂的有效成分的常规分析 ,直至进入2 0世纪 90年代后才在农药国际标准分析方法 (CIPAC)手册中相继出现。近年来 ,随着大口径毛细管推广应用和一些重大技术的改进 ,毛细管气相色谱作为农药的常规分析方法 ,发展比较快。到目前为止 ,CIPAC已经建立了近 2 0个农药原药及其制剂的毛细管气相色谱标准分析方法。大口径毛细管气相色谱法具有分析…     

The Chemical Characterization of Potential Organic Interferences in Two Commercially Available Polymeric Adsorbents

Abstract

Current use of synthetic adsorbents for the collection of trace organics in environmental samples is quite extensive. It has been suggested that high levels of organic contaminants in these resins may interfere with subsequent analyses, however, the identity of these suspected contaminants has not been reported.

This paper reports a qualitative and quantitative characterization of the residual organics in two polymeric adsorbents.

Both resins are commercially available polymers of styrene divinyl-benzene. The structures of the contaminants were verified by combined gas chromatography/mass spectrometry (GC/MS). High artifact levels are typical for both of the Amberite® resins studied. The majority of these materials, as verified by capillary GC/MS, were alkyl derivatives of benzene, styrene, naphthalene and biphenyl.     

离子排斥色谱法测定有机酸的研究

研究了利用高效离子排斥色谱（ＨＰＩＣＥ）和电导检测器分离和测定有机酸的色谱条件。选用低电导的辛烷磺酸为淋洗液，对８种有机酸的分离条件进行了研究，并将该法应用于化学镀镍液中有机酸的分析，结果令人满意。