Study of Competitive Chelating Reaction between Lanthanum and Tribromoarsenazo in the Medium of Weak Acid by Capillary Zone Electrophoresis

Two kinds of metal chelates of rare earth elements reacted with tribrimoarsenazo formed under the condition of critic acid were observed by simultaneous technique of capillary electrophoresisphotothermal interference spectrometry. The tendency of the conversion between these chelates as functions of the mole ratio of the reagent and the metal, pH value and the elapsing time was investigated. Kinetic equation of competitive chelating reaction between the TBA-La (Ⅲ) and La (Ⅲ) -critic acid were established. It was found that the competitive chelating reaction follows secondorder kinetics, for this second-order reaction, k=5.55 L·mol-1·S-1.

Quantification of Porcine Follicle-stimulating Hormone Receptor Messenger Ribonucleic Acid by Reverse Transcription competitive Polymerase Chain Reaction

An easy and reliable method was developed for construction and quantification of competitive templates, which shared the same sequence as the amplified target DNA except for a 20 bp insertion in the middle by recombinant polymerase chain reaction (PCR). Among the advantages of competitive PCR is that any predictable or unpredictable variable that affects amplification has the same effect on both target and competitor species and that the final ratio of amplified products reflects exactly the initial targets. The utilization of a thermostable reverse transcriptase in the RT step was proposed to overcome the problem of the efficiency of target cDNA synthesis. In addition, to obtain reliable measurements, it was recommended to perform four PCR with amounts of competitive template flanking the concentration of the target mRNA.

Liquid-Phase Catalytic Hydrogenation of Furfural in Variable Solvent Media

Water is the most abundant compound inherently existing in bio-oils. Thus understanding the role of water within bio-oils upgrading process is essential for future engineering scale-up design. In this study, furfural was chosen as bio-oils model compound, and the catalytic hydrogenation of furfural over commercial 5%, Ru/C catalyst was firstly investigated in a series of gradient variable water/ethanol mixture solvents. Water had a significant effect on the distribution of product yields. The dominant reaction pathways varied with the water contents in the water/ethanol mixture solvents. Typically, when ethanol was used as the solvent, the main products were obtained by the hydrogenation of carbonyl group or furan ring. When pure water was used as the solvent, the rearrangement reaction of furfural to cyclopentanone should be selectively promoted theoretically. However, serious polymerization and resinification were observed herein in catalytic hydrogenation system of pure water. The catalyst surface was modified by the water-insoluble polymers, and consequently, a relative low yield of cyclopentanone was obtained. A plausible multiple competitive reaction mechanism between polymerization reaction and the hydrogenation of furfural was suggested in this study. Characterizations(TG,FT-IR,SEM)were employed to analyze and explain our experiments.

Characterization the Reaction of Isocyanate and Cellulose by XPS

The X-ray photoelectron spectroscopy (XPS) technique was used to study the reaction ofphenyl isocyanate and cellulose with different moisture contents (MC). The C1S XPS peak of cellulose isonly one symmetrical contribution at 285.95 eV. While the C1S XPS peaks of N,N-dibenzylurea, thereaction resultant of phenyl isocyanate and water, have two contributions at 288.6±0.1 eV and 284.7±0.1 eV corresponding to the carbonyl group and phenyl ring group, respectively. Their area ratio isbetween 11.88 and 11.98 that is quite neat to the theoretical value of 12.0. With the moisture content (MC)of cellulose increased, the proportion of isocyanate reacted with water increased. When the MC reaches 9.78%, 92.98% of all consumed isocyanate will react with water. By spattering analysis, it reveals that thereaction resultants of benzyl isocyanate distribute mainly on the surface of cellulose.