Rapid separation of beryllium and lanthanide derivatives by capillary gas chromatography

Previous studies describe derivatization of metal ions followed by analysis using gas chromatography, usually on packed columns. In many of these studies, stable and volatile derivatives were formed using fluorinated β‐diketonate reagents. This paper extends previous work by investigating separations of the derivatives on small‐diameter capillary gas chromatography columns and exploring on‐fiber, solid‐phase microextraction derivatization techniques for beryllium. The β‐diketonate used for these studies was 1,1,1,2,2,6,6,7,7,7‐decafluoro‐3,5‐heptanedione. Derivatization of lanthanides also required addition of a neutral donor, dibutyl sulfoxide, in addition to 1,1,1,2,2,6,6,7,7,7‐decafluoro‐3,5‐heptanedione. Unoptimized separations on a 100‐μm i.d. capillary column proved capable of rapid separations (within 15 min) of lanthanide derivatives that are adjacent to one another in the periodic table. Full‐scan mass spectra were obtained from derivatives containing 5 ng of each lanthanide. Studies also developed a simple on‐fiber solid‐phase microextraction derivatization of beryllium. Beryllium could be analyzed in the presence of other alkali earth elements (Ba(II) and Sr(II)) without interference. Extension of the general approach was demonstrated for several additional elements (i.e. Cu(II), Cr(III), and Ga(III)).     

进口原油、天然气检验监管的安全、环保和反欺诈技术

讨论了进口原油和天然气检验监管工作、包括科研工作重点应该转移到从安全、环保、卫生、反欺诈等方面把好国门的必要性和紧迫性。提出了加快研制和开发现场、快速、高通量检测仪器、装置和传感器等建议。     

流动注射在线液-液萃取火焰原子吸收法测定水中痕量铅

提出了一种流动注射在线液－液萃取火焰原子吸收直接测定水中痕量铅的分析方法。实验以APDC为螯合剂,用MIBK为萃取剂,研究了在线萃取中各种实验参数、酸度条件的影响,考察了共存元素的干扰。方法的RSD（n=12)为2．7％,测定检出限为3．1μg/L,回收率为96％－106％。     

乙酸乙酯合成反应的实时在线拉曼光谱测量

本文报道一种用于在线拉光谱测量的技术。可以在工业生产过程中对产品的成分和工作条件进行实时的监测,在本实验中,用我们自己研制的光纤探头,配合现有的拉曼光谱装置对合成乙酸乙酯的化学反应过程进行了实时跟踪测量。得到了反应过程中乙醇-,乙酸和乙酸乙酯的拉曼光谱,从谱图分析了它们的特征峰与时间的关系,从而可由这些结果确定在此实验条件下反应物与生成物的浓度随时间的变化,进而可确定反应过程完成的时间。     

圆柱面波的复惠更斯源展开

本文提出一种分析波场问题的新方法——复惠更斯源展开法,它用具有复数坐标的次波源代替普通的次波源,根据复射线理论求解各次波源的贡献,并按叠加原理而构成初波源的场.文中讨论了二维波场的这种展开.只要适当选择展开参量,该方法相对于严格理论解的误差不大于1%.     

A method for distinguishing power-law and approximate power-law behavior in glassy relaxation: Ionic conducting glasses

The question of whether an apparent power-law behavior in the ac conductivity of glasses is a real power-law, or is the product of a factor linear in the frequency and logarithmic corrections is important for the interpretation of the data. The former behavior is predicted by theories which invoke scaling relations a priori and attribute the frequency dependence to hierarchical scaling, multifractal scaling, or anomalous diffusion on fractal structures. The latter behavior is a natural result of a pair approximation. A simple procedure is suggested for the purpose of distinguishing the two possibilities. The procedure involves plots of the locus of ordered pairs of frequency and temperature for which the imaginary part of the dielectric constant is a constant.     

d-Proline capped gold nanoclusters for turn-on detection of serum Raltitrexed

With d-proline as the reducing and capping agent, fluorescent gold nanoclusters were rapidly prepared (d-Pro@AuNCs) within 10 min at 100 °C. In the present of gold nanoparticles, the fluorescence of d-Pro@AuNCs was remarkably quenched. Interestingly, based on the electrostatic interaction between anticancer drug Raltitrexed and gold nanoparticles induced fluorescence “turn-on” principle, a high selective assay for detection of Raltitrexed was established with the probe associating the fluorescence emission at 435 nm. The fluorescence intensity of d-Pro@AuNCs linearly correlated with the concentration of Raltitrexed in the range from 5.0 μmol/L to 40.0 μmol/L (R² = 0.999) and the limit of detection was 1.9 μmol/L. Further, after Raltitrexed was abdominal injected in rats, a metabolic approach was constructed with the prepared fluorescent probe. It showed great potential of AuNCs-based sensing probes for application in analysis of serum anticancer drugs.     

Design and synthesis of novel type VI-like β-turn mimetics. Diversity at the i+1 and the i+2 position

In this paper, a synthetic approach for functionalised 5-aminopiperidinone-2-carboxylate (APC) systems as non-pro cis-peptide bond containing external β-turn mimics is presented. The scope and limitations of the synthetic method are discussed and the potential turn inducing properties of a model compound are evaluated by means of molecular modelling and NMR analysis.     

阿司匹林合成过程的在线拉曼光谱研究

利用在线拉曼光谱的方法,跟踪阿司匹林合成反应过程的实验.直接观测到反应过程中体系的拉曼光谱随时间的变化,用小波变换的方法去除光谱的本底之后, 又利用多波长线性回归的方法对实验数据进行实时的处理,得到了实验中各组分的相对浓度随时间的变化.     

填充毛细管液相色谱-毛细管气相色谱在线联用技术

建立了一套填充毛细管液相色谱－毛细管气相色谱在线联用的二维色谱分离体系。联用接口由十通阀和多位阀构成，将经填充毛细管液相色谱分离后的样品各馏分在线准确切割和储存，并在线无损失输送至ＧＣ分析，从而实现了复杂样品的一次进样全组分的分离分析。