电致化学发光研究的新进展

综述了近１０年来国内外电致化学发光（ＥＣＬ）在分析化学上的研究及应用情况。根据反应类型对ＥＣＬ进行了分类，阐述了它们的反应机理，并展望了ＥＣＬ的发展趋势。     

流动注射在线阴离子树脂预富集火焰原子吸收测定痕量铜

研究了以阴离子交换树脂作吸附剂的流动注射在线微柱预富集火焰原子吸收测定铜的新方法。在最佳条件下富集１５０ｓ，富集２３倍，检出限０．２μｇ／Ｌ，ＲＳＤ为１．６％，分析速度２０次／ｈ。天然水样中可能存在的离子不干扰铜的测定。所建立的方法已用于水样中痕量铜的测定。     

膜富集分光光度法测定微量锌

以５－Ｂｒ－ＰＡＤＡＰ为显色剂，用ＷＸ型混合纤维素滤膜（孔径０．６５μｍ，φ２５ｍｍ）富集微量锌，用乙醇溶解富集物（Ｚｎ（Ⅱ）－５－Ｂｒ－ＰＡＤＡＰ）分光光度法测定锌，Ｚｎ（Ⅱ）－５－Ｂｒ－ＰＡＤＡＰ在乙醇溶液中最大吸收波长为５５５ｎｍ，表观摩尔吸光系数１．０９×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，锌量在０．１～５．０μｇ／５ｍＬ，范围内符合比耳定律，本法灵敏度高，操作简便，应用于食品，水样中锌     

水中非离子型表面活性剂的富集分离和高灵敏光度测定研究

用改性ＰＶＡ树脂，从水中富集痕量合成非离子型表面活性剂（ＳＮＳ），进一步用ＳＮＳ与钡盐和磷钼酸定量地形成难溶缔合物沉淀，使ＳＮＳ与共存物分离浓缩。用Ｍｏ－邻苯二酚紫－溴化十二烷基吡啶（ＤＰＢ）显色反应（表面摩尔吸光系数εｍａｘ值为３．１×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾＿１）体系分光光度测定与ＳＮＳ定量缔合的Ｍｏ，从而间接测定水中痕量ＳＮＳ。方法用于江，湖水中痕量ＳＮＳ的测定，获得较好结果。     

仙茅根茎中的配糖体

仙茅ｏ以社ＯｒｃｈｉｏｄｅｓＧａｅｒｔｎ）为石蒜科植物仙茅的根茎,具温肾阳,壮筋骨,治阳萎精冷,小便失禁,崩漏,心腹冷痫,腰脚冷痹,痈且,瘦瘦之功效ｌ’］。久保道德［２１分离获得的仙茅威（Ｃｕｒｅｕｌ－ｇＯＳｉｄ经药理实验证明能大幅度促进巨噬细胞的增生能力和吞噬作用,提高人体免疫功能。在云南省陇川县采集仙茅的根２５３０９,经＊ｅＯＨ热提取后,硅胶柱层析,＊ＨＣ卜Ｍｅ规梯度洗脱,反相【卜１８柱层析,ＭｅＯＨ爿ｐ洗脱纯化。得到７个化合物（－Ｇ）。化合物Ａ为首次从该植物中分离获得。Ｆ为一个新三荫眈本文…     

叶黄素的几类降解反应研究

类胡萝卜素是一大级一泛存在于动植物体内的四储类化合物,它们不仅颜色鲜艳,也是一类重要香味物质的前体。在Ｍ的烟０－Ｉ中已有１８种类型的胡萝卜素被分离和日表征。其中卜胡萝卜素和叶黄素是主要成分ｌ‘］。烟叶采收后,类胡萝卜素经生物降解,会生成一系列有挥发性芳香化合物,它什对卷烟的吸味、品质有很大的影响Ｉ２］。本文设计了四种化学方法,对叶黄素进行氧化降解,产物用ＧＣ／ＭＳ进行检测。结果表明,在适当条件下对叶黄素进行化学法氧化降解,可以得到如：氢化异佛尔酮、环氧紫萝兰酮、二氢弥猴桃内＠纺ｏ茶香螺酮等有重要…     

轻质石油产品电导率仪检定系统分析

论述研制轻质石油产品电导率仪检定系统的必要性,介绍各级检定标准装置的原理和检定方法。     

Selective extraction of strontium with supercritical fluid carbon dioxide

Strontium (Sr(2+)) can be selectively extracted from aqueous solutions into supercritical fluid CO(2) at 60 °C and 100 atm with dicyclohexano-18-crown-6 (DC18C6) using CF(3)(CF(2))(6)CO(2) (-) (PFOA(-)) or CF(3)(CF(2))(6)CF(2)SO(3) (-) (PFOSA(-)) as a counter anion; at a mole ratio of Sr(2+) : DC18C6 : PFOA(-) = 1:10:50, the extraction of Sr (5.6 × 10(-5) M) from water at pH 3 is near quantitative whereas Ca(2+) and Mg(2+) at equal concentration are only extracted to a level of 7 and 1%, respectively; PFOSA(-) is an effective counter anion for selective extraction of Sr(2+) from 1.3 M HNO(3) with DC18C6 in supercritical CO(2).     

Anodic stripping voltammetric determination of bismuth(III) using a Tosflex-coated mercury film electrode

A Tosflex-mercury film electrode (TMFE) was prepared by spin-coating a solution of the perfluorinated anion exchange polymer Tosflex onto a glassy carbon electrode surface followed by electrodeposition of mercury film on this electrode. This electrode was used for the determination of trace bismuth(III) which was preconcentrated onto the TMFE as anionic bismuth(III) complexes with chloride in a chloride medium. The preconcentration was carried out at a potential of-0.2 V, and the preconcentration of the bismuth(III) was enhanced significantly by the anion-exchange feature of Tosflex. The accumulated bismuth(III) was then determined by anodic square-wave stripping voltammetry (SWSV). Various parameters influencing the determination of bismuth(III) were examined in detail. With 2 min accumulation, the analytical signal versus concentration dependence was linear up to 50 ppb, and the detection limit was 0.58 ppb. This modified electrode showed good resistance to the interferences from surface-active compounds and common ions.     

Measurement of dioxygen by electrocatalytic reduction on microelectrodes modified with Nafion and methyl viologen

Nafion/methyl viologen (MV) has been chemically modified on a gold disk microelectrode (GDME). The electrochemistry of the Nafion/MV modified GDME is investigated by cyclic voltammetry (CV). Linear sweep voltammetry (LSV) and differential pulse amperometry (DPA) show that the Nafion/MV modified GDME exhibits very high electrocatalytic activity toward dioxygen reduction with good reproducibility and high sensitivity. The electrocatalytic peak current is found to be linear with the dioxygen concentration in the range of 3.44x10(-7) to 2.59x10(-4) mol l(-1) (at 25 degrees C), with a correlation coefficient of 0.9978. The detection limit (signal/noise=3) is calculated to be 0.19 mumol l(-1). The response time of the microsensor for dioxygen measurement is less than 15 s. For ten parallel measurements for 8.50 mumol l(-1) dioxygen, the relative standard deviation (RSD) is found to be 2.7%. The sensitivity of the microsensor is 0.17 nA mumol(-1) l(-1). This microsensor has been successfully employed to measure the concentration of dioxygen in real samples. The quantity of dioxygen, released from the three kinds of chloroplasts of plant leaves under different illumination, is monitored by the Nafion/MV modified gold microsensor. In order to survey the dioxygen concentration in vivo, a Nafion/MV modified carbon fiber microelectrode (CFME) is fabricated by a modification procedure similar to that of the Nafion/MV GDME. As a preliminary test, the dioxygen levels in the different areas of rat brain are determined by the Nafion/MV modified carbon fiber microsensors. The mechanism of the catalytic reaction is also addressed.