Using electrospray laser desorption ionization mass spectrometry to rapidly examine the integrity of proteins stored in various solutions

Electrospray laser desorption ionization mass spectrometry (ELDI/MS) allows the rapid desorption and ionization of proteins from solutions under ambient conditions. In this study, we have demonstrated the use of ELDI/MS to efficiently examine the integrity of the proteins stored in various solutions before they were further used for other biochemical tests. The protein standards were prepared in the solutions containing buffers, organic salts, inorganic salts, strong acid, strong base, and organic solvents, respectively, to simulate those collected from solvent extraction, filtration, dialysis, or chromatographic separation. Other than the deposit of a drop of the sample solution on the metallic sample plate in an ELDI source, no additional sample pretreatment is needed. The sample drop was then irradiated with a pulsed laser; this led to desorption of the analyte molecules, which subsequently entered the ESI plume to undergo post-ionization. Because adjustment of the composition of the sample solution is unnecessary, this technique appears to be useful for rapidly evaluating the integrity of proteins after storage or prior to further biochemical treatment. In addition, when using acid-free and low-organic-solvent ESI solutions for ELDI/MS analysis, the native conformations of the proteins in solution could be detected.

Radioactive 129I in surface water of the Celtic Sea

Relatively large amounts of radioactive iodine ¹²⁹I (T _1/2  = 15.7 Ma) have been documented in seawater such as the English Channel, the Irish Sea and the North Sea. Data on the concentration of the iodine isotopes in waters of the Celtic Sea are missing. Aiming to provide first ¹²⁹I data in the Celtic Sea and compare them with levels in the other close-by seawater bodies, surface seawater samples were analyzed for the determination of ¹²⁷I and ¹²⁹I concentrations. The results revealed a high level of ¹²⁹I in these waters and suggest strong influence by liquid discharges from La Hague and Sellafield reprocessing facilities. ¹²⁷I concentrations are rather constant while the ¹²⁹I/¹²⁷I ratio reaches up to 2.8 × 10^?8 (ranging from 10^?10 to 10^?8), which is 2–4 orders of magnitude higher than pre-nuclear era natural level. Transport of ¹²⁹I to the Celtic Sea is difficult to depict accurately since available data are sparse. Most likely, however, that discharges originated from La Hague may have more influence on the Celtic Sea ¹²⁹I concentrations than the Sellafield. Comprehensive surface water and depth profiles ¹²⁹I data will be needed in the future for assessment of environmental impact in the region.     

手性高效液相色谱法测定1—（6‘—甲氧基萘）乙醇不对称氢酯基化反应

在自制的硅基纤维素－三（３，５－二甲基苯基氨基甲酸酯）高效液相色谱手性固定相上（ＨＰＬＣ－ＣＳＰ），优化了１－（６＇－甲氧基萘）乙醇氢酯基化反应产物－萘普生甲酯手性分离的条件，测定了相应的一系列不对称氢酯基化反应产物的对映体过剩值（ｅ．ｅ．值）。结果表明，在ＣＤＭＰＣ－ＣＳＰ手性柱上用ＨＰＬＣ测定此类不对称催化反应的光学产率，评价催化剂体系的手性选择是一种非常理想的方法。     

NdCl3-FeCl3-石墨层间化合物的合成

采用熔盐交换法成功地合成了ＮｄＣｌ３ＦｅＣｌ３ＧＩＣ, 用ＸＲＤ 技术和Ｘ射线能谱仪（ＥＤＳ） 对其层间结构及各元素的相对含量进行了表征。研究表明, 其结构为２,３ ,４ 阶混合结构,３ 阶ＮｄＣｌ３ 的特征层间距为１－６５３６ ±０－００２４ ｎｍ , 并探讨了稀土氯化物石墨层间化合物的形成机制。     

C60正丙胺铂,铑配合物的合成及其催化硅氢化性能

Ｃ６０与正丙胺反应,然后分别与氯亚铂酸钾或三氯化铑配合,制得出含配位氮原子的富勒烯铂,铑 配合物,它们均能有效地催化烯烃与三乙氧基硅烷硅氢加成,铂配合物还对苯乙烯有独特的催化性能,以近１００％的区域选择性得到α－加成产物,对催化机理进行了初步的探讨。     

离子色谱法测定增味剂中的5′-肌苷酸二钠和5′-鸟苷酸二钠

 建立了增味剂中5′-肌苷酸二钠和5′-鸟苷酸二钠的离子色谱分析方法。采用lonPacASll阴离子交换色谱柱,以20mmol／LNa2CO3一体积分数为15％的甲醇溶液为淋洗液,检测波长254um。方法已用于实际样品的测定。     

合成1，3－二（3－羟丙基）四甲基二硅氧烷的新方法

用二乙氧基二甲基硅烷与３－氯丙醇反应，合成了新化合物３－氯丙氧基乙氧基二甲基硅烷，然后用格氏反应代替Ｗａｌｔｅｒ的钠缩合反应，最后经水解制备了１，３－二（３－羟丙基）四甲基二硅氧烷，总收率为４２．０％。     

α－甲基丙烯酸烯丙酯的合成及其自由基、阴离子聚合的研究

合成了α－甲基丙烯酸烯丙酯（ＡＭＡ），并对其自由基、阴离子聚合进行了探讨。结果发现，该单体难以进行选择性自由基聚合，但可用作多种单体自由基聚合的交联剂。用１，１′－二苯基己基锂在ＴＨＦ中引发ＡＭＡ，可顺利地进行α位双键的选择性阴离子聚合，分子量实测值与计算值基本一致。在较低温度下（≤－６０℃），可得窄分布ＰＡＭＡ（Ｍｗ／Ｍｎ＝１．１２～１．１５）。随聚合温度升高，间同和无规聚合物含量分别呈下降和上升趋势。ＧＰＣ、１ＨＮＭＲ及ＦＴＩＲ鉴定表明，用阴离子聚合法可得到溶于多种溶剂、每个重复单元上均定量带有烯丙基双键的窄分布官能性ＰＡＭＡ。