电感耦合等离子体质谱法测定人血浆中20种微量元素

建立了人血浆样品中微量元素的ICP-MS测定方法。分析了100名健康成人和50名健康儿童血浆样品的20种微量元素,给出了参考值范围。该方法检出限为0.0001~1.60μg/L;精密度(RSD)介于0.78%~4.27%;多数元素回收率在100%±10%之内。方法简便(正常人血浆经超纯水,硝酸,TritonX-100,正丁醇稀释后直接测定其中的微量元素),快速,样品用量少(血浆0.2mL),可作为人体内多种微量元素的监测方法,同时为人血浆中微量元素正常值范围的确定提供了参考依据。     

硒的激光—时间分辨荧光分析

本文介绍了一种以PTQA作荧光增强剂,用激光-时间分辨发光分析仪测定硒的新方法。PTQA与Se(Ⅳ)反应,其产物经激发可产生荧光(λ_(ex)/λ_(em)=357 nm/495 nm)。在0.02ng/ml～10 ng/ml范围内,硒浓度与荧光强度呈正相关(r≥0.999),方法灵敏度为0.02 ng/ml。文中推荐了方法的最佳测量条件,并用标准牛肝粉(NBS1577a)进行了检验。     

一种二维自适应网格构造方法及其实现

讨论了一种二维自适应网格的构造方法,在二维插值法的基础上做出了自适应网格。最后利用自适应网格技术对一个二维流体力学问题的实例进行了计算。     

脉冲熔融-飞行时间质谱法测定Nd-Fe-B材料中的氧、氮、氢

建立了脉冲熔融-飞行时间质谱法测定Nd-Fe-B材料中的氧、氮、氢的方法,在选定的实验条件下,氧、氮、氢的检出限分别为0.021,0.060,0.002μg/g;利用系列标准样品得到各元素的校准曲线,线性相关系数R2均大于0.99。将方法应用于Nd-Fe-B材料的测定,经对比实验验证,方法测定值与传统的脉冲熔融-红外/热导方法测定值相符合。     

Enzymatic digestion and chromatographic analysis of arsenic species released from proteins

A method combining gel filtration chromatography (GFC), protease digestion, and ion pair chromatography with inductively coupled plasma mass spectrometry detection was developed for the determination of arsenic species bound to proteins. The method was first established by examining the interactions of two model proteins, metallothionein (MT) and hemoglobin, with three reactive trivalent arsenic species. It was then successfully applied to the speciation of arsenic in red blood cells of rats. Inorganic arsenite (iAs^III), monomethylarsonous acid (MMA^III), and dimethylarsinous acid (DMA^III) were efficiently released from the proteins by protease digestion at pH 8.0, with the recovery ranging from 93% to 106%. There was no oxidation of iAs^III or MMA^III during the protease digestion process. Up to 61% DMA^III (the least stable arsenic species) was unchanged, and the rest was oxidized to the pentavalent dimethylarsinic acid (DMA^V). The arsenic species in the red blood cells of control rats was present as DMA^III complex with hemoglobin. The method enabling the determination of the specific arsenic species that bind to cellular proteins is potentially useful for studying arsenic distribution, metabolism, and toxicity.     

铜催化苯甲酰胺有氧环化合成7-叔烷基异喹啉二酮

发展了一种高效、简单的铜/空气催化体系催化的苯甲酰胺串联自由基环化合成7-叔烷基异喹啉二酮的反应。 在廉价CuI存在下,空气环境中,N-烷基-N-甲基丙烯酰基苯甲酰胺与AIBN发生串联自由基加成/环化/碳碳偶联反应,以52%~73%的产率合成了一系列的7-取代异喹啉二酮。 此研究为合成具有潜在药用价值的含氰取代异喹啉二酮提供了一条快速、简单、温和的构建途径。     

Van der Waals Heterostructured MOF‐on‐MOF Thin Films: Cascading Functionality to Realize Advanced Chemiresistive Sensing

Heterostructured metal—organic framework (MOF)‐on‐MOF thin films have the potential to cascade the various properties of different MOF layers in a sequence to produce functions that cannot be achieved by single MOF layers. An integration method that relies on van der Waals interactions, and which overcomes the lattice‐matching limits of reported methods, has been developed. The method deposits molecular sieving Cu‐TCPP (TCPP=5,10,15,20‐tetrakis(4‐carboxyphenyl)porphyrin) layers onto semiconductive Cu‐HHTP (HHTP=2,3,6,7,10,11‐hexahydrotriphenylene) layers to obtain highly oriented MOF‐on‐MOF thin films. For the first time, the properties in different MOF layers were cascaded in sequence to synergistically produce an enhanced device function. Cu‐TCPP‐on‐Cu‐HHTP demonstrated excellent selectivity and the highest response to benzene of the reported recoverable chemiresistive sensing materials that are active at room temperature. This method allows integration of MOFs with cascading properties into advanced functional materials.     

Mo-La_2O_3阴极碳化层组织结构研究

采用高分辨透射/扫描电镜,X射线衍射和俄歇探针等分析手段对实用型的FU-6051电子管的碳化Mo-La2O3阴极显微组织结构进行了观察分析。碳化Mo-La2O3阴极碳化层为疏松多孔的Mo2C块状组织,其中有许多垂直于丝轴方向的晶界与孔洞串,相互贯通直至阴极表面。碳化层与芯部基体钼结合良好,两者间无明显的过渡层。活性物质La2O3在阴极的碳化层和基体中分布均匀,但在阴极表面有相当程度的富集。La2O3在碳化层中以两种方式存在:在晶界、孔洞中以微米级的颗粒富集,在Mo2C晶体内部弥散分布纳米级La2O3粒子。     

EFFECT OF POLYMERIZATION CONDITIONS ON THE LADDERLIKE STRUCTURE OF POLYPHENYLSILSESQUIOXANE

The ladderlike structure of PPSQ synthesized by using four kinds of catalysts (MgF_2,LiF, KOH and DCC) at different polymerization conditions has been investigated by IRand NMR. In the system using MgF_2 as the main catalyst, the most important factorwhich affects the ladderlike structure of PPSQ is the composition of the dual catalysts,MgF_2 and DCC. PPSQ prepared by using KOH as the catalyst has the highest regularityof ladderlike structure among all samples. PPSQ with different degree of ladder regularitycan be obtained by choice of polymerization conditions.     

人血清白蛋白柱上药物的手性拆分

考察了４种酸性药物和１种中性药物对映体在人血清白蛋白手性固定相上的保留行为。这５种药物与人血清白蛋白结合的亲和力高，难于实现快速分离，作者提出在流动相中加入短链脂肪酸－正己酸，可快速手性拆分非诺洛芬、萘普生和布洛芬。酮基布洛芬对映体分离选择性随乙腈浓度升高而增大，流动相中加入适量异丙醇可使对映体选择性大大增加（α～１．２３），华法令同样可取得很好分离。