异烟酸在银溶胶上的表面增强喇曼散射及影响因素

本文研究了异烟酸吸附在银溶胶表面的表面增强喇曼散射(SERS)光谱以及卤素离子、溶液pH值及溶液浓度对异烟酸SERS光谱的影响。文章提出了离子在银溶胶表面的吸附方式,即主要以—COO~-端吸附于银溶胶表面。最后,对所述实验现象作了定性讨论。     

Studies on the Spectral Behavior between Protein with Poniacyl Carmine 2B and its Analytical Application

In this paper, the spectral behavior of protein and Poniacyl Carmine 2B (PC 2B) has been studied by spectrophotometric method. The conditional constants, apparent combination constant K and maximum binding number n, were used to express the combination ability of the reactions between PC 2B and protein under a set of given conditions. The Sandell index s was used to express the sensitivity of the determination of protein. The factors, acidity, PC 2B concentration and the ionic strength, were discussed by the change of apparent combination constant and maximum binding number. It was found that acidity of the solution, PC 2B concentration and ionic strength had a significant effect on the sensitivity of the assay of protein. Under the optimal conditions, the apparent combination constant K and the maximum binding number n were 2.36 × 10⁶ L mol^?1 and 95, respectively. With further investigation, it was found that the Scatchard model was suitable in treating the data obtained in the experiments. In the buffer medium of HCl‐KCl at 1.87, the addition of protein made the maximum absorption of the system move from 527 nm to 513 nm. Its apparent molar absorptivity is 4.46 × 10⁵ Lmol^?1 cm^?1 at 513 nm. Beer's law is obeyed in the range of 0 ? 55 μg mL^?1. The system developed in this paper has been used for the determination of protein in milk powder successfully.     

Ru/Mn-Ce/TiO2催化剂催化湿式氧化丁二酸的反应活性和动力学研究

在二氧化钛载体中通过掺杂Ru，Mn，Ce制备了一系列用于催化湿式氧化的催化剂，利用XRD，TEM，BET等手段对催化剂进行了表征．在反应温度T=210～270℃，氧分压Po2=2．1MPa条件下，在间歇式高压反应釜中对丁二酸进行了降解实验．催化剂在反应中有很高的催化活性．催化剂在30min内对丁二酸降解的COD去除率为54．4～98．3％．Ru及Mn，Ce的氧化物对催化活性都有促进作用．建立了丁二酸催化湿式氧化的一级分段动力学模型．基于COD的一段及二段反应的活化能分别为43．74kJ／mol和54．28kJ／mol．     

A vacuum ultraviolet photoionization mass spectrometric study of acetone

The photoionization and dissociative photoionization of acetone have been studied at the photon energy range of 8-20 eV. Photoionization efficiency spectra for ions CH3COCH3+, CH3+, C2H3+, C3H3+, C3H5+, CH(2-)CO+, CH3CO+, C3H4O+, and CH3COCH2+ have been measured. In addition, the energetics of the dissociative photoionization has been examined by ab initio Gaussian-3 (G3) calculations. The computational results are useful in establishing the dissociation channels near the ionization thresholds. With the help of G3 results, the dissociation channels for the formation of the fragment ions CH3CO+, CH2CO+, CH3+, C3H3+, and CH3COCH2+ have been established. The G3 results are in fair to excellent agreement with the experimental data.     

Determination of Dextromethorphan and its Metabolite Dextrorphan in Human Hair by Gas Chromatography–Mass Spectrometry

An analytical method has been developed for determination of dextromethorphan (DMP) and dextrorphan (DRP) in human hair by gas chromatography–mass spectrometry (GC–MS). Hair samples (30 mg) were washed with distilled water and acetone and cut into small fragments (<1 mm) before extraction with methanol. The extracts were evaporated to dryness and then derivatized by use of BSTFA containing 1% TMCS, for preparation of the trimethylsilyl (TMS) derivative of DRP. The extract (1 μL) was then injected into the GC–MS. Recoveries of DMP and DRP at 7.0 and 22.5 ng mg^?1 were in the range 90.6–97.2% with intra-assay and inter-assay precision of less than 5.7% and 4.7%, respectively. LOD and LOQ were, respectively, 0.67 and 2.13 ng mg^?1 for DMP and 0.14 and 0.47 ng mg^?1 for DRP. The responses were linear with correlation coefficients (r > 0.9995) for the drugs studied. The applicability of the method was proven by analysis of authentic hair samples.     

Transfer Hydrogenation of C= C Double Bonds Catalyzed by Ruthenium Amido-Complexes: Scopes, Limitation and Enantioselectivity

The reduction of C = C double bonds is one of the most fundamental synthetic transformations and plays a key role in the manufacturing of a wide variety of bulk and fine chemicals. Hydrogenation of olefinic substrates can be achieved readily with molecular hydrogen in many cases, but transfer hydrogenation methods using suitable donor molecules such as formic acid or alcohols are receiving increasing attention as possible synthetic alternatives because it requires no special equipment and avoids the handling of potentially hazardous gaseous hydrogen.     

微铂电极上1-酰基二茂铁动力学参数的测定

本文合成并研究了１－酰基二茂铁在ＣＨ２Ｃｌ２中的伏安行为，测定了它们在ＣＨ２Ｃｌ２中不同支持电解质浓度时的扩散系数，并分明用Ｚ．Ｇａｌｕｓ和Ｋ．Ａｏｋｉ方法计算了两种状态下的电子迁移速率常数。讨论了取代基的诱导效应和共轭效应及其链长对１－酰基二茂铁的动力学性质的影响以及支持电解质及其浓度等因素对伏安曲线的影响。     

SnO2-Nb2O5/MgAl2O4/α-Al2O3催化环氧乙烷水合制乙二醇

采用水热稳定的MgAl2O4尖晶石对-αAl2O3载体表面进行修饰,采用具有较强亲水性能的SnO2对活性组分Nb2O5进行修饰,制备了SnO2-Nb2O5/MgAl2O4/-αAl2O3催化剂,并用于环氧乙烷水合制乙二醇反应.采用X射线衍射、红外光谱和程序升温脱附研究了Sn/Nb摩尔比对催化剂酸性、环氧乙烷在催化剂表面的吸附状态和吸附强度以及催化剂性能的影响.结果表明,Sn/Nb摩尔比明显影响催化剂的组成和结构;催化剂的结构不同,环氧乙烷在催化剂表面的吸附强度存在明显差别,催化剂的催化性能明显不同.