等温平台石墨炉原子吸收光谱法测定高纯镍中痕量杂质锑

利用石墨炉原子吸收法，在等温平台条件下直接测定高纯镍中的痕量杂质锑，对石墨炉加热程序中的干燥时间、灰化温度及原子化温度进行了优化，同时考察了介质酸度的影响。试验表明，基体镍对锑的测定有显著的影响，为此进行了标准系列基体匹配。该法的特征质量为6．6pg；相对标准偏差为6．5％；加标回收率为100％-103％。     

对DSC单峰纯度测定法的评述

指出了当前流行的差示扫描量热法DSC单峰法测样品纯度所基于的假定有一些不确切的地方,并用计算机动态摸拟了DSC实验过程,结果证实了本文的论断。     

Reproducible method to enrich membrane proteins with high purity and high yield for an LC‐MS/MS approach in quantitative membrane proteomics

The proportionately low abundance of membrane proteins hampers their proteomic analysis, especially for a quantitative LC‐MS/MS approach. To overcome this limitation, a method was developed that consists of one cell disruption step in a hypotonic reagent using liquid nitrogen, one isolation step using a low speed centrifugation, and three wash steps using high speed centrifugation. Pellets contained plasma, nuclear, and mitochondrial membranes, including their integral, peripheral, and anchored membrane proteins. The reproducibility of this method was verified by protein assay of four separate experiments with a CV of 7.7%, and by comparative LC‐MS/MS label‐free quantification of individual proteins between two experiments with 99% of the quantified proteins having a CV ≤30%. Western blot and LC‐MS/MS results of markers for cytoplasm, nucleus, mitochondria, and their membranes indicated that the enriched membrane fraction was highly pure by the absence of, or presence of trace amounts of, nonmembrane marker proteins. The average yield of membrane proteins was 237 μg/10 million HT29‐MTX cells. LC‐MS/MS analysis of the membrane‐enriched sample resulted in the identification of 2597 protein groups. In summary, the developed method is reproducible, produces a highly pure membrane fraction, and generates a high yield of membrane proteins.     

差示扫描量热法测定除草剂绿麦隆的纯度

研究了用差示扫描量热法(DSC)测定绿麦隆的纯度。该法测定最佳条件为升温速率0.5 K.min-1,样品量2~3 mg,保护气流速20 mL.min-1。用本法测得绿麦隆原药的纯度为98.35%,相对标准偏差(RSD)为0.034%,测定结果与已知纯度相符。并将测定结果与高效液相色谱(HPLC)法进行了比较。该法具有操作简便,样品用量少,准确度和精密度均较高等优点。     

Hypericin and Pseudohypericin. Purity Criteria and Quantitative Determination in Extracts of Saint John’s Wort (Hypericum perforatum)

Summary. Hypericin and pseudohypericin in extracts of St. Johns Wort (Hypericum perforatum) are assayed using UV-Vis, measuring the absorbance at 588nm of a methanolic solution of the compounds. The value of the absorption coefficient is difficult to define insofar as none of the routine purity criteria can be applied to these two compounds. Analysis of the entire UV-Vis spectrum from 220 to 740nm would seem to be a reliable way of comparing different samples. A UV-Vis spectrum was recorded for each of the compounds using a Photodiode array detection system. A more accurate way of determining the levels of hypericin and pseudohypericin in extracts of St. Johns Wort using these reference spectra is described.     

Equational Compactness of G-sheaves

Purity and equational compactness play a role at least in the Theories of Modules, Acts, Model, and Category. Adámek and Rosický have studied them categorically, Rothmaler model-theoretically, and some authors, including Banaschewski, Gould, and Normak have studied these notions on G-acts. We take both the group G and the set A in the definition of a G-act to be sheaves and study equationally compact G-sheaves. We get different kinds of equationally compact G-sheaves, study them and their interrelations, give some conditions for their proper behavior, and generalize some of the existing results.     

基于二极管阵列检测器的色谱峰纯度的快速直观鉴定

基于二极管阵列检测器（DAD）得到的色谱-光谱图,通过去噪、归一化、计算欧氏距离,聚类分析等方法,建立了一种快速直观的评价色谱峰纯度的有效方法：可直观的判断色谱峰的纯度,并判断存在干扰峰的位置,为色谱工作者评价色谱峰,进行下一步工作提供了依据。     

石墨炉原子吸收法测定高纯镍中痕量铋

本文利用石墨炉原子吸收法，在等温平台条件下直接测定了高纯镍中的痕量铋，并对石墨炉加热程序中的干燥时间，灰化温度及原子化温度进行了优化，同时也考察了介质酸度的影响，试验表明：基体镍对铋的测定有显著的影响，为此对标准系列进行了基体匹配，本方法的特征质量为6．1pg，相对标准偏差为3．6％，加标回收率为99．3％－104％。     

Quantifying temperature and flow rate effects on the performance of a fixed-bed chromatographic reactor

Chromatographic reactors are based on coupling chemical reactions with chromatographic separation in fixed-beds. Temperature and flow rate are important parameters for the performance of such reactors. Temperature affects mainly adsorption, chemical equilibria, mass transfer and reaction kinetics, whereas flow rate influences residence time and dispersion. In order to evaluate the mentioned effects, the hydrolysis reactions of methyl formate (MF) and methyl acetate (MA) were chosen as case studies. These reactions were performed experimentally in a lab-scale fixed-bed chromatographic reactor packed with a strong acidic ion exchange resin. The chosen reactions can be considered to represent a relative fast (MF) and a relative slow (MA) reaction. The processes which take place inside the reactor were described and simulated using an isothermal equilibrium dispersive model. The essential model parameters were determined experimentally at different temperatures and flow rates. The performance of the chromatographic reactor was evaluated at several discrete constant temperature levels by quantifying product purity, productivity and yield. The work provides insight regarding the influence of temperature and flow rate on values of the model parameters and the performance criteria.     

ICP－AES测定核纯海绵锆中17个杂质元素方法的研究

应用ＩＣＰ－ＡＥＳ法，对核纯海绵锆中１７个杂质元素的测定进行了试验研究。取样量１００ｍｇ时，Ａｌ、Ｃａ、Ｃｏ、Ｃｒ、Ｃｕ、Ｆｅ、Ｍｇ、Ｍｎ、Ｍｏ、Ｎｉ、Ｐｂ、Ｓｎ、Ｔａ、Ｔｉ、Ｖ、Ｙ和Ｚｎ的测定范围是１０μｇ／ｇ—３２００μｇ／ｇ。回收率为９５．２％—１０６．５％。