Monitoring myoglobin by capillary zone electrophoresis with end-column amperometric detection

Capillary zone electrophoresis was employed for the determination of myoglobin in human urine using end-column amperometric detection with a carbon fiber microelectrode at a constant potential of 1.80 V vs. saturated calomel electrode (SCF). The optimum conditions of separation and detection are: 3.73 x 10-4 mol/L sodium diethyl malonyl urea (barbitone sodium), 1.34 x 10-4 mol/L HCl for the buffer solution, 20 kV for separation voltage, 5 kV and 5 s for injection voltage and injection time, respectively. The limit of detection is 4.4 x 10-8 mol/L or 84 amole signal to noise (S/N = 2). The relative standard deviation is 2.9% for the migration time and 2.5% for the electrophoretic peak current. The method can be used for the determination of myoglobin in human urine. The samples can be directly injected and need no pretreatment. The method is also rapid, less than 2 min, and has a recovery rate of 94-106%.     

Theoretical investigation of the decarbonylation of acetaldehyde by Fe+ and Cr+.

We report a comprehensive theoretical study on the decarbonylation of acetaldehyde by Fe+ and Cr+. Various intermediates, transition states, and products involved in the decarbonylation reactions are fully optimized at the B3LYP/6-311+G(2df,2pd) level of theory. The potential energy surfaces (PESs) corresponding to [M,O,C2,H4]+(M=Cr and Fe) are examined in detail using B3LYP and CCSD(T) methods, respectively. The validity of these theoretical methods is calibrated with respect to the available thermochemical data. Calculations suggest that the Cr+ mediated decarbonylation of acetaldehyde takes place in four steps on the sextet surface: encounter complexation, C-C activation, aldehyde H-shift, and nonreactive dissociation, in good accordance with the Co+ mediated decarbonylation of acetaldehyde [Zhao, Zhang, Guo, Wu, Lu, Chem. Phys. Lett. 2005, 414, 28], while for the Fe+/acetaldehyde system decarbonylation can occur on both the quartet and the sextet PESs. The quartet pathway, which experiences spin-orbit coupling between the two surfaces, is energetically more favorable; whereas along the sextet decarbonylation coordinate several high-energy barriers are revealed. The theoretical results are compared with the experimental product kinetic energy and angular distributions of decarbonylation of acetaldehyde by Fe+ and Cr+ measured using a crossed-beam technique [Sonnenfroh, Farrar, J. Am. Chem. Soc. 1986, 108, 3521].     

PPC/SBR并用弹性体的配方选择

利用正交法对丁苯橡胶（SBR）／聚丙撑碳酸酯（PPC）共混弹性体进行配方设计，得到了一个具有良好综合性能的配方。并通过方差分析得出PPC含量和马来酸酐（MA）用量是影响弹性体拉伸性能的最显著因素。     

人尿中诺龙和炔诺酮代谢物的气相色谱-质谱分析

本文对合成的19-去甲雄烷醇酮的四个差向异构体混合物进行气相色谱分离,对诺龙和炔诺酮用药后,留取的人尿样通过化学预处理,MSTFA/TMSI衍生化反应,GC/MS分析,确证了尿样中诺龙的两个主要代谢产物为19-去甲雄酮和19-去甲原胆烷醇酮,炔诺酮的两个主要代谢物是四氢炔诺酮(THINE)的两个形式,可能是3α-OH-5α-THINE和3α-OH-5β-THINE,在炔诺酮代谢前期,还发现有诺龙的上述两个代谢物存在。     

SYNTHESIS AND CATALYTIC PROPERTY OF POLYSTYRENE SUPPORTED GLUTAMIC ACID SCHIFF BASE COMPLEX OF Mn（ Ⅱ ） IN AEROBIC OXIDATION OF CYCLOHEXENE

The polystyrene supported glutamic acid Schiff base complex of Mn （ Ⅱ ） （PS-Sal-Glue-Mn） was prepared with chloromethylated styrene polymer beads, 2,4-dihydroxybenzaldehyde, L-glutamic acid and manganese （ Ⅱ ） acetate tetrahyrate. The polymeric ligand and the complex were characterized by FT-IR, small area X-ray photoelectron spectroscopy （XPS） and 1CP-AES. In the presence of the manganese complex, cyclohexene （1） was effectively oxidized by molecular oxygen without reductant. The major products of the reaction were 2-cyclohexen-l-ol （2）, 2-cyclohexen-l-one （3） and 2-cyclohexen-1- hydroperoxide （4）, which was different with typical oxidation of cyclohexene. The influence of reaction temperature and additive for oxidation had been studied. The selectivity of 2-cyclohexen-1-hydroperoxide varied with reaction time and different additives. The mechanism of cyclohexene oxidation had also been discussed.     

新型紫外衍生试剂用于D-氨基酸的毛细管电泳分离

采用一种新型紫外衍生试剂对乙酰氨基苯磺酰氟(PAABS-F)作为柱前衍生试剂,成功地对19种标准D-氨基酸和甘氨酸进行了衍生和毛细管电泳分离。详细研究了各种分离条件对毛细管电泳分离的影响。实验结果表明:采用20 mmol/L硼砂(pH 9.3),126 mmol/L十二烷基硫酸钠,8 mmol/Lβ-环糊精和20mmol/L NaC l时分离结果最佳,16 m in内实现了20种氨基酸的基线分离。     

硅胶键联MPc的制备及其在氧活化中的作用

过渡金属酞等配合物（MPC）用手均相液相氧化中作催化剂已有不少报导，象许多均相催化剂一样，MPC用于均相反应存在着难于从反应体系中分离出来的问题．把均相配合物催化剂固载在无机氧化物如硅股或有机高分子载体上是解决这一问题的一种方法．我们曾尝试把MP。固载在分子筛载体和硅胶载体上，并用ESR研究其对O2的活化作用[1，2]．本文报导MPc通过共价键键联固载在SiO2上，并研究其对O2的活化作用．1实验部分1．1试剂HSIC13为日本东京化成株式会社产品，二级试剂·发烟硫酸（SO。质量分数大于20％）为分析纯试剂．PCl5为化学纯试…     

Synthesis and characterization of a new isocyanato carborane anion [7-OCN-7-CB10H12]; study on its reactivity toward amino containing compounds

The new isocyanato carborane anion, [7-OCN-7-CB₁₀H₁₂]⁻ was prepared by the reaction of 7-H₃N-7-CB₁₀H₁₂ with triphosgene in the presence of triethylamine. The structure of this compound was established by ¹H, ¹¹B and ¹³C NMR as well as IR spectroscopy. The reactivigty of this compound with a series of organic amines was investigated. The resulting ureas were obtained in good to excellent yields. This approach is suitable for development of compounds for use in tumor selective Boron Neutron Capture Therapy (BNCT).     

便携式GC-MS在应急监测工作中的应用

在2006年一次突发性有机物污染事故中,运载30吨液态危险品(苯乙烯)的槽罐车,发生侧翻,部分运输物质泄漏到农田中,用便携式GC-MS进行应急监测,取得了良好的效果.     

氨基酚异构体的离子对反相液相色谱分析的研究

本文研究了离子对反相液相色谱分析氨基酚异构体的可能性、影响因素和色谱条件，发现以含４×１０－８ｍｏｌ／Ｌ四丁基碘化铵、０．１８４ｍｏｌ／Ｌ醋酸钠的甲醇水溶液（２３：７７）作为流动相，ＯＤＳ为固定相时可以实现氨基酚异构体的良好分离。