A simple and mild derivatization method for hydroxyl compounds using condensation agent carbazole-9-N-(2-methyl)-acetyl-benzene-disulfonate and its application for the determination of volatile alcohols from plasma by HPLC with fluorescence detection

A simple and sensitive HPLC method for the determination of hydroxyl compounds including volatile alcohols from spiked plasma, using a fluorescent condensation agent, namely carbazole-9-N-(2-methyl)-acetyl-benzene-disulfonate (CMABS), has been developed. A mixture of alcohols and pyridine in dichloromethane was treated with CMABS to give a quantitative yield of esters. The maximum fluorescence emissions for the derivatized alcohols are at 365 nm (λ_ex 335 nm). Studies on derivatization conditions indicate that alcohols react very fast with CMABS in presence of pyridine in dichloromethane to give the corresponding fluorescent derivatives. The method, in conjunction with a multi-step gradient, offers a baseline resolution of the common alcohol derivatives on a reversed-phase C₁₈ column, which is more convenient and more efficient than previous methods which require the prior conversion of the carboxylic acids to the acyl chlorides. The application of this method to the analysis of volatile alcohols in plasma was also investigated. The LC separation shows good selectivity and reproducibility for alcohol derivatives. The relative standard deviations ?(n = 5) for 100 pmol of each alcohol are < 4%. The detection limits are at the fmol level for C₁–C₃ alcohols and pmol level for C₄–C₉ alcohols. Received: 9 November 1998 / Revised: 3 May 1999 / Accepted: 6 May 1999     

Study of the chromatographic behavior and inclusion constants of new fluorescence agents by use of cyclodextrin additives under conditions of steady- and dynamic-state equilibrium and with fluorescence detection

Summary We report four new derivatization agents, acridone-N-acetic acid (ARC), carbazole-9-ylacetic acid (CRA), carbazole-9-ylpropionic acid (CRP), and 2-methyl-2-carbazole-9-ylacetic acid (MCRA), with strong fluorescence emission which has low dependence on solvent polarity. The emission maxima for ARC, CRA, CRP, and MCRA were 430 nm (λ_ex 404 nm), 368 nm (λ_ex 335 nm), 356 nm (λ_ex 340 nm) and 360 nm (λ_ex 330 nm), respectively. The effects of mobile-phase composition, pH, and temperature on the liquid chromatographic retention behavior of the four fluorescence agents were investigated. An experimental model was established for calculating the inclusion constants of cyclodextrin (CD) complexes in the dynamic state, using β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD) as examples, and different mobilephase compositions. On the basis of the model, the inclusion constants of the solutes in pure water (K _fw) were determined by extrapolation. The thermodynamic parameters (ΔH ^o and ΔS ^o) and dissociation constantsK _am for the solutes in this chromatographic system were obtained by means of capacity factor (k) values using a corresponding model formulation.     

微型化快速病原体检测生物分析装置的研制

研制一种能够快速检测和筛选细菌以及病毒微生物,并且能够对动物体内致病载体进行现场监测的完整的微分析装置具有十分重大的意义.这种便携式的生物分析系统不需要繁杂的仪器设备就能进行复杂的生物样品分析,并由一般的未经训练的个体在短时间内完成操作过程.     

金属镍吸附氢同位素的量子力学计算

根据原子分子反应静力学与群论，确定了ＮｉＨ、ＮｉＤ和ＮｉＴ的基电子状态为２Σ＋。应用基函数６－３１１Ｇ和组态相关ＣＩ或ＱＣＩＳＤ方法，计算了氢同位素分子及其镍化物的能量Ｅ、定容热容Ｃｖ和熵Ｓ。设用总能量中的电子和振动能量近似代表ＮｉＨ、ＮｉＤ和ＮｉＴ分子处于固态时的能量，用总熵中的电子和振动熵近似代表这些分子处于固态时的熵，进而计算了镍吸附Ｈ２、Ｄ２和Ｔ２分子过程的ΔＨ°、ΔＳ°、ΔＧ°和平衡压力，并导出它们与温度的函数关系。计算指出了同位素分子效应，结果合理。所以，本文所建议的用量子力学方法计算多相化学反应，有应用参考价值。     

The preparation of silver absorbers for sampling airborne mercury

Microchimica Acta - The procedure for the preparation of MC-8 silver absorbers is described. Silver gauze, 30–60 mesh, is used after heat activation at 800°. The construction of the...     

分子烙印聚合物作超临界流体萃取后处理用固体吸附剂

利用离线超临界流体萃取与高效毛细管电泳相结合，分析了标准添加样品中的除草剂（2，4－二氯苯氧乙酸（2，4－D）），探讨了温度、压力和改性剂对萃取的影响，考察了在不同条件下合成的2，4－D为烙印分子的子烙印聚合物对2，4－D在不同极性溶剂中的吸附能力，并将分子烙印聚合物作为超临界流流体萃取后处理用固体吸附剂，结果表明，在甲醇和水的混合极性溶剂中制备的分子烙印聚合物对提高分析选择性的效果最佳。     

糖尿病人血清18种元素与肾功能、血脂、心功能等因素的分析

测定56例非胰岛素依赖型糖尿病人血清Cu、Se、Zn、Cr、Mn、Fe、Co、V、Cd、Pb、B、Al、Sr、As、Ti、Ni、Ba、Mg等18种微量元素，并以上述18种元素分别作为因变量，以血糖、血脂、肾功能、心功能等指标为自变量，作多因素逐步回归分析．能建立回归方程的微量元素有Cu、Mn、Zn、Co、Fe、Sr、Se、Cd、B、Mg、Ba．糖代谢有关的FBG、PBG、GHb均未能进入模型。能进入模型有与肾功能有关的CR、β2-Mg、Pu，与血脂代谢有关的TG、TC、LDL-Ch、VLDL-Ch、HDL-Ch及与心功能有关的EF．糖尿病人血清Cu、Mn、Co与病人的肾功能指标(CR、β2-Mg或Pu)相关，Mn、Se、Cd、B、Mg、Ba与血脂代谢指标相关，Zn、Co、Mg与心脏EF相关．