Analysis of sugar phosphates in plants by ion chromatography on a titanium dioxide column with pulsed amperometric detection

This paper describes the development of a practical method for the analysis of sugar phosphates from the model higher plant Arabidopsis thaliana by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The extraction method of sugar phosphates from higher plants was first optimized for HPAEC-PAD analysis. In order to improve the resolution in HPAEC-PAD, a column packed with titanium dioxide resin was used. The titanium dioxide column was used as a trap-column for sugar phosphates and nucleotides, for the removal of sample matrices. Sample pretreatment was achieved in-line and automatically using a six-port valve placed after the injection valve.     

Thermal membrane potential across cation-exchange membranes for various halide solutions

Thermal membrane potential across cation-exchange membranes was measured for various halide solutions. Linear relationships between thermal membrane potential () and temperature difference (T) were observed, and the temperature coefficient of thermal membrane potential (/T) decreases with increase in the molality of the external solution as predicted by a theory reported. When counterions of membranes are hydrogen ions, the sign of the coefficients turns into minus near 0.01 mol/kg of the external solution for all membranes, although the coefficients are always positive for all the other forms. The dependence of the coefficients on the molality of the external solutions sometimes deviated slightly from the theory. This deviation is attributed to some change in water content of the membranes. A reproducible method of measuring water content of membranes was applied to discuss the change in the state of the membranes.     

New boron nitride whiskers: showing strong ultraviolet and visible light luminescence

Boron nitride whiskers with a special structure have been synthesized by a thermal reaction process. The as-prepared BN whiskers have a length of tens of micrometers and a mean diameter of 500 nm. High-resolution TEM analysis shows that the as-prepared BN whiskers can be described as a nanofiber-interweaved network. Infrared and electron energy loss spectra reveal that the BN whiskers are composed of both sigma-sp2 and sigma-sp3 chemical bonds. The UV-vis absorption spectrum displays the energy band gap of the BN whiskers and multiple fine absorption peaks of the phonon-electron coupling. Both photoluminescence (PL) and cathodoluminescence (CL) measurements show the specially structured BN emits strong UV and visible luminescences, which is a promising material for deep-blue and UV applications.     

Aromatic nucleophilic substitution—II : Intermediates in the reactions of 2,4-dinitro- or 2,4,5-trinitro-1-naphthyl ethyl ether with secondary amines and preparation of a spiro meisenheimer complex

The intermediates in the reactions of 2,4-dinitro-(2) or 2,4,5-trinitro-1-naphthyl ethyl ether (11) with secondary amines have been studied. In the reaction of 2 with piperidine, the NMR spectrum of the reaction system indicated the coexistence of the three species-starting material, Meisenheimer complex, and substituted product. In the reaction of 11 with piperidine or N-methyl-n-butylamine, the the NMR spectra of the reaction system indicated the presence of a Meisenheimer complex, but did not indicate the formation of a substituted product. In addition, the spiro Meisenheimer complex (9) was prepared from 1-[N-methyl-(2′-hydroxy)ethylamino]-2,4,5-trinitronaphthalene (8) and sodium methoxide.     

INERTEAR毛细管在芳香烃碳六组份分析上的应用

苯在常压非等温平衡等离子体(DBD)加氢反应过程中,主要生成环己烯,环己二烯和环己烷.要优化加氢反应条件,首先要解决分析问题.本文提出了用INERTEAR毛细管柱分析测定了芳香烃碳六组份含量的分析方法,研究了其测定条件,并确定了各组份的定量校正因子.为常压下研究微型等离子体反应器中进行芳香烃苯加氢的反应奠定了基础.