固相微萃取-气相色谱联用技术分析混合气体中微量氢

制备钯-5A分子筛萃取头,使用固相微萃取-气相色谱联用技术,建立了对混合气体中微量氢气的分析方法.实验结果表明,含氢浓度在0.0011~0.1250 mL/L范围内,具有良好线性关系,检出限为9×10-4mL/L.此方法和气相色谱法比较,有更高的灵敏度和更少的干扰,2种方法的标准偏差为8.7%.     

Simultaneous isolation and determination of esculin and rutin in natural materials using SPE and HPLC

Summary Esculin (ESC) and rutin (RUT) have been simultaneously isolated from pharmaceutical natural materials by solid phase extraction (SPE). Determination of both substances was performed by reversed phase high performance liquid chromatography (RPHPLC) with UV detection. Optimization of the separation conditions showed that simultaneous isolation and determination of rutin and esculin from pharmaceutical material was possible. The recovery obtained was not lower than 95±2%.     

1-苯基-3-甲基-4-苯甲酰基-5-吡唑酮与甲基膦酸二(1-甲基庚基)酯对Pb(Ⅱ)、Cd(Ⅱ)和Cu(Ⅱ)的萃取机理研究

本文用两相滴定法研究了1-苯基-3-甲基-4-苯甲酰基-5-吡唑酮(PMBP,简写为HA)与甲基膦酸二(1-甲基庚基)脂(P_(350),简写为B)对Pb~(2+)、Cd_(2+)和Cu~(2+)离子在不同的有机溶剂中的萃取机理.(?)定了萃合物的组成分别为:MA_2(M=Pb~(2+)、Ca~(2+)、Cu~(2+));MA_2·HA(M=Cd~(2+));MA_2·B(M=Pb~(2+)、Cd~(2+))和MA_2·2B(M=Cd~(2+)),同时求得了相应的萃合常数β值.     

二氧化碳与丙烯直接合成甲基丙烯酸用CuPMo／TiO2催化剂的研究

 用溶胶－凝胶法以磷钼酸（MPA）的铜盐溶液水解钛酸四丁酯制备了CuPMo／TiO2催化剂，并用ICP，XRD，TG－DTA，IR，TPD－MS和微反技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化性能．结果表明：杂多钼酸盐与TiO2表面通过O2－桥发生键联．在623K下，杂多阴离子仍保持其原有的Keggin结构；CO2在Lewis酸位Cu（Ⅱ）和Lewis碱位Cu－O－Mo桥氧的协同作用下形成卧式吸附态Cu（Ⅱ）←O－（CO）←（O－－Cu）；丙烯以分子吸附态在催化剂上吸附；在空速1500h－1，压力1MPa和温度563K的反应条件下，丙烯的转化率为4．2％，甲基丙烯酸的选择性为96％．     

Gas-stirred solvent extraction with propylene carbonate for separation and direct polarographic determination of thallium (III)

Gas-stirred propylene carbonate (PC) extraction can be performed by bubbling nitrogen without loss of volume. This extraction technique has proved to be highly useful for the separation and subsequent direct polarographic estimation of Tl(III) in the recovered PC phase. Tl(III) can be determined by differential-pulse polarography over the concentration range of 0.4 10 g ml^–1 without any interferences due to most metal ions such as Pb(II), Bi(III), Cu(II), Sb(III) and As(III). This proposed technique would be possible to use as a simple extraction step prior to the final estimation by instrumental method of analysis such as atomic absorption spectrometry or spectrophtometry.     

聚合物支载噁唑类化合物在不对称反应中的应用

聚合物支载噁唑类化合物主要包括聚合物支载噁唑烷酮、噁唑啉和硼杂噁唑啉等,其在不对称反应中主要用作手性助剂、手性催化剂及催化剂配体.由于其便于分离提纯、可以回收重复使用且立体选择性没有明显降低等优点在不对称反应中得到了广泛的应用.综述了近年来聚合物支载的噁唑类化合物在不对称反应中的应用     

Fiber-in-Tube Solid Phase Extraction (FIT-SPE) for Miniaturized Sample Preparation Process

A typical analytical separation procedure has several important steps: sample preparation, isolation, identification, quantitation, statistical evaluation and final decision. Each step is alwayscritical to obtain correct results to fulfill the analytical purpose. In these various steps sample     

新型含金属元素二胺的合成与表征

本文分别用液相法和固相法合成了一系列含不同金属元素的二胺,并通过红外光谱,~1HNMR、~(13)CNMR,紫外光谱,电化学分析及元素分析对其进行表征,还通过DSC和TG对其热性能进行了研究,结果发现这些二胺具有良好的耐热性,是合成一些耐热高聚物的优良原料.     

Cyanex272-P507浸渍树脂协同萃取色层分离铥镱镥的研究

以Cyanex272-P507浸渍树脂采用萃取色层法对铥镱镥富集物进行了吸附和淋洗分离研究,考察了淋洗剂浓度、稀土负载量、淋洗液流速等因素对分离铥镱镥富集物的影响。结果表明,在充填的树脂粒度为0.3~0.6 mm的色层柱中,以0.2 ml.cm-2.min-1进料流速时能得到较大的吸附率;在稀土负载量为树脂重量的0.6%,淋洗液流速为1.0 ml.cm-2.min-1,温度为30℃,装柱树脂高度为400 mm(高径比为25∶1)的条件下,用1.0,1.5,2.0 mol.L-1盐酸梯度淋洗Tm,Yb,Lu,可实现铥镱镥富集物三者的完全分离。