ICP-AES法测定高温质子导体中的五种元素

研究用ICP-AES法测定高温质子导体中的钡、铈、锶、钇和镱，选定了适宜的溶解方法及分析条件，在溶解酸中加入盐酸羟胺，获得了较为满意的分析结果，相对标准差小于10%。     

One-pot preparation of mono-dispersed and physiologically stabilized gold colloid

We have developed a rapid and simple method for the preparation of nearly mono-dispersed gold colloids with a fairly high concentration above 10 mM using hydroxylamine as the reducing agents, in the presence of α-methoxy-ω-mercaptoethyl-poly(ethylene glycol)(MeO-PEG-SH). It was found that a hydroxylamine acted not only as a reducing agent, but also as a nucleation agent under alkaline reaction conditions. Though the colloid concentration was fairly high, the dispersion stability was remarkably improved even in a high ionic strength in the range greater than 1 M NaCl, in which conventional citrate gold colloids immediately flocculate and precipitate. The obtained colloid was successfully re-dispersed in aqueous media after lyophilization. In addition, the prepared gold colloid reduced a protein adsorption significantly on its surface. Concerning these results, the obtained colloidal dispersion may be suitable for biological applications, since a regionally concentrated colloidal dispersion with dispersion stability is required for bio-labeling and bio-imaging systems.Electronic Supplementary Material Supplementary material is available for this article at     

Synthesis of N-aryl and N-heteroaryl hydroxylamines via partial reduction of nitroarenes with soluble nanoparticle catalysts

Polystyrene-supported ruthenium nanoparticles enable the selective hydrazine-mediated reduction of nitroarenes to hydroxylamine products in high yield and selectivity. Key to obtaining the hydroxylamine product in good yield was the use of organic solvents capable of solubilizing the polystyrene-supported nanoparticle catalyst. N-aryl and N-heteroaryl hydroxylamines are generated under exceptionally mild conditions and in the presence of a various easily reduced functional groups.     

Electrocatalytic Synthesis of Pyridine Oximes using in Situ Generated NH2OH from NO species on Nanofiber Membranes Derived from NH2-MIL-53(Al)

Pyridine oximes produced from aldehyde or ketone with hydroxylamine (NH₂OH) have been widely applied in pharmaceutics, enzymatic and sterilization. However, the important raw material NH₂OH exhibits corrosive and unstable properties, leading to substantial energy consumption during storage and transportation. Herein, this work presents a novel method for directly synthesizing highly valuable pyridine oximes using in situ generated NH₂OH from electrocatalytic NO reduction with well-design nanofiber membranes (Al-NFM) derived from NH₂-MIL-53(Al). Particularly, 2-pyridinealdoxime, the precursor of antidote pralidoxime (2-PAM) for nerve agents suffering from scarcity and high cost, was achieved with a Faraday efficiency up to 49.8 % and a yield of 92.1 %, attributing to the high selectivity of NH₂OH production on Al-NFM, further easily reacted with iodomethane to produce 2-PAM. This study proposes a creative approach, having wide universality for synthesizing pyridine and other oximes with a range of functional groups, which not only facilitates the conversion of exhaust gas (NO) and waste water (NO₂⁻) into valuable chemicals especially NH₂OH production and in situ utilization through electrochemistry, but also holds significant potential for synthesis of neuro detoxifying drugs to humanity security.     

Synthesis of Enantiomerically Pure Isoxazolidine Monomers for the Preparation of β3‐Oligopeptides by Iterative α‐Keto Acid?Hydroxylamine (KAHA) Ligations

A versatile method for the synthesis of enantiomerically pure isoxazolidine monomers for the synthesis of β³‐oligopeptides via α‐keto acid? hydroxylamine (KAHA) ligation is presented. This one‐pot synthetic method utilizes in situ generated nitrones bearing gulose‐derived chiral auxiliaries for the asymmetric 1,3‐dipolar cycloaddition with methyl 2‐methoxyacrylate. The resulting enantiomerically pure isoxazolidine monomers bearing diverse side chains (proteinogenic and non‐proteinogenic) can be synthesized in either configuration (like‐ and unlike‐configured). The scalable and enantioselective synthesis of the isoxazolidine monomers enables the use of the synthesis of β³‐oligopeptides via iterative α‐keto acid? hydroxylamine (KAHA) ligation.     

An Indirect Polarograpric Method for the Determination of Periodate Oxidizable Organic Compounds

Abstract

An indirect polarographic method is described based on the alprade reaction. The formaldehyde produced is determined by its decrease of the hydroxylamine a-c polarographic wave. Sorbitol, ethanediol, mannitol, ethanolamine, serine and threonine are determined in the range 5 – 30 × 10^?6 M while 2.5 – 10 × 10^?6 M triethanolamine are determinable.     

Copper-promoted rearrangement of 1,3-cyclohexadiene-acylnitroso cycloadducts

The ring opening of [2.2.2]-acylnitroso cycloadducts was obtained for the first time by means of a cationic rearrangement promoted by Cu(OTf)₂-PPh₃ under homogeneous and polymer-supported conditions.     

Chemiluminescence Sensor for the Determination of Hydroxylamine by Electrostatically Immobilizing Luminol and Periodate

IntroductionAnalytical methods based on chemilumi-nescence( CL ) reactions have received considerableattention for theirapplication in various fields,ow-ing to their extremely high sensitivity along withother advantages such as wide linear dynamicrange,simple instrumentation,easy miniaturiza-tion and coupling to various separation tech-niques[1— 6] .CL sensors have been developed for be-ing used as the continuous and real- time monitorsof inorganic,organic,biological and pharmaceuti-cal comp…