钪-乳酸-2-(5-溴-2-吡啶偶氮)-5-二乙氨基苯酚-Triton-X-100体系的显色反应及应用研究

在pH8.1～8.8,有 Triton X-100存在下,Sc(Ⅱ)与乳酸(L)及 5-Br-PADAP(R)形成胶束混配络合物。该络合物最大吸收波长为565nm,表观摩尔吸光系数为6.08×10～4L·mol～(-1)·cm(-1)。络合物组成为Sc:L:R=1:1:2。由于乳酸的存在,显色体系灵敏度和选择性都得到提高。本法用PMBP萃取分离干扰组分后,可测定钨矿及其浸出渣中微量钪,相对标准偏差为1.7％～2.7％。     

苯酚、马尿酸和甲基马尿酸的反相高效液相色谱分析

本文提出了人体内苯、甲苯和二甲苯的代谢产物苯酚、马尿酸和甲基马尿酸的反相高效液相色谱分析法,讨论了其保留机制和样品预处理技术.以ODS为固定相,甲醇-水-醋酸为流动相时可实现良好分离.方法回收率为97.3%,相对标准偏差为1.02%.提出的方法可用于尿样分析,适用于临床与职业病防治的监测分析.     

2-乙基己基磷酸单(2-乙基己基)酯萃淋树脂分离-火花源质谱法测定高纯氧化镱中痕量稀土杂质

本文采用萃取色谱法以2-乙基已基膦酸单(2-乙基已基)酯(P_507)萃淋树脂为固定相,以HCI-NH_4CI体系为淋洗液,研究了99.999%~99.9999%的高纯Yb_2O_3中稀土杂质和Yb基体的分离条件,将杂质淋洗液富集于复合螯合剂-活性碳上,经灼烧灰化后制成样品电极,进行质谱测定.测定下限达 0.01~0.05 μg/g,可用于高纯 Yb_2O_3中杂质的测定.回收率在80%以上.     

毛细管电泳在手性分离中的应用及进展

本文评述了近年来毛细管电泳在手性分离中的应用及进展，介绍了毛细管电泳分离手性对映射的数学模型、五种不同的分离模式及机理、七种常用的手性选择性类型及其在药学、环境和生命科学中的应用、研究中需优化的操作参数及其发展方向。     

XRF分析铁矿粉的标准选择判据研究和应用

本文对ＸＲＦ法分析铁矿的基体校正元素进行了研究，并建立了标准选择判据，编制的计算软件可以自动地从大量标样中选择适合该样品分析的标准。该法可用于粉末压片制样的分析，方法快速，准确度和精密度均符合生产要求。     

甲苯气相选择性氧化制苯甲醛 Ⅰ．V_2O_5／TiO_2－Al_2O_3催化剂研究

制备了一系列负载型Ｖ－Ｔｉ－Ａｌ－Ｏ催化剂并用于甲苯的气相选择性氧化制苯甲醛，考察了接触时间、氧浓度、Ｖ２Ｏ５负载量以及催化剂焙烧温度对反应性能的影响。用ＴＰＲ、ＸＲＤ和ＢＥＴ等测试手段，对催化剂进行了表征。研究发现，催化剂在７７３Ｋ时活化，接触时间１．２秒，氧浓度２１％时，可获得较好的反应结果，Ｖ２Ｏ５负载量为６（ｗｔ）％的催化剂，在５９３Ｋ时反应，得到了转化率２０．５％，苯甲醛产率８．３％的最好结果。     

Can curcumin food and <Emphasis Type="Italic">Bacillus subtilis</Emphasis> drug be taken simultaneously?

Curcumin (CUR), a frequently-used food additive and flavorings, has been reported to be safe at a wide dose range. Bacillus subtilis (B. subtilis) is commonly found in soil and decomposing organic matter, and it was reported beneficial for humans when ingested. Up to now, there have been no contraindication of B. subtilis except for the avoidance of the drug combination with antibiotics, and the interaction of food and B. subtilis drug is blank. In this study, the interaction of CUR and B. subtilis was investigated. Microcalorimetry was applied to evaluate the effect of CUR on B. subtilis growth. By analyzing the main parameters extracted from the heat-flow power–time curves, it was concluded that CUR could inhibit the growth of B. subtilis, and the 50% inhibiting concentration (IC₅₀) valued 109.9 μg mL⁻¹. The results revealed that it is unreasonable to take CUR and B. subtilis at the same time, and it also provided a new way for the investigation of the interaction between food and drug. Meanwhile, this study indicated that the safety of CUR should be re-evaluated.     

Additive-assisted Rupe rearrangement of 1-ethynylcyclohexan-1-ol in near-critical water

We performed the Rupe rearrangement of 1-ethynylcyclohexan-1-ol in near-critical water to study the reaction under high temperature conditions. The final product thus obtained was primarily 1-cyclohexen-1-ylethanone which was identified by GC-MS. The influences of reaction time, temperature, and initial reactant-to-water ratio on the yield of 1-cyclohexen-1-ylethanone were examined. The yield of 1-cyclohexen-1-ylethanone was 49 % in pure water at 260°C for a reaction time of 60 min. However, when additives such as ZnSO₄, FeCl₃, and NaHSO₄, respectively, were introduced to the water to investigate the effect of salts on the Rupe rearrangement reaction, the yield increased markedly to as much as 88 % in 5 mole % NaHSO₄ aqueous solution under the same conditions. The catalytic ability of the additives decreased in order: NaHSO₄, FeCl₃, ZnSO₄. On the basis of these results, a possible reaction mechanism of the Rupe rearrangement of 1-ethynylcyclohexan-1-ol in near-critical water was proposed.     

Stannum film electrode for square wave voltammetric determination of trace copper(II)

An anodic stripping voltammetric procedure for the determination of Cu(II) at an in situ-plated stannum film electrode (SnFE) was described. The results indicated that the SnFE had an attractive electroanalytical performance, with two distinct voltammetric stripping signals for copper and stannum, and showed the superior advantage for the determination of copper compared with the bismuth film electrode. Several experimental parameters were optimized. The SnFE exhibited highly linear behavior in the concentration range from 1.0 to 100.0 μg L⁻¹ of Cu(II) (r = 0.994) with the detection limit of 0.61 μg L⁻¹ (S/N = 3), and the relative standard deviation for a solution containing 40.0 μg L⁻¹ Cu(II) was 2.2% (n = 8). The procedure has been successfully applied for the determination of Cu(II) in lake water sample.     

Gold-Catalyzed Regioselective Dimerization of Aliphatic Terminal Alkynes

A gold-catalyzed regioselective homodimerization of aliphatic terminal alkynes is described. Bulky and less Lewis acidic tBuXPhosAuNTf(2) is the preferred catalyst, and the additive, anhydrous NaOAc, substantially facilitates the reaction.