A method for the analysis of low-mass molecules by MALDI-TOF mass spectrometry

We report a novel method termed matrix suppressed laser desorption/ionization to improve the analysis of low-mass molecules by MALDI-TOF mass spectrometry. In this method, the surfactant of cetrimonium bromide (CTAB) is added to the conventional matrix of alpha-cyano-4-hydroxycinnamic acid solution to prepare the MALDI samples. During the MALDI process, the presence of CTAB could substantially or even completely suppress the matrix-related ion background. As a result, very clean mass spectra can be routinely obtained in the low-mass range. In addition, the presence of CTAB can significantly improve the mass resolution of low-mass molecules. It is seen that high-quality spectra were routinely obtained at a matrix/CTAB ratio of 1000:1. This method has been successfully used to analyze a variety of low-mass molecules.

Recent progress in adsorbed stationary phases for capillary electrochromatography

This review surveys the recent progress in the adsorbed stationary phases for capillary electrochromatography (CEC). Adsorption-based methods for preparation of stationary phase are novel approaches in CEC, which allow rapid and facile preparing stationary phases with desirable selectivity onto an open-tubular fused-silica capillary, a baresilica or ion-exchange packed column or a monolithic silica or polymer column. A variety of adsorbing agents have been developed as adsorbed stationary phases, including ionic long-chain surfactant, protein, peptide, amino acid, charged cyclodextrin (CD), basic compound, aliphatic ionene, and ion-exchange latex particle. The adsorbed stationary phases have been applied to separation of neutral, basic and acidic organic compounds, inorganic anions and enantiomers. They have also been applied to on-line sample concentration, fast separation and study of the competitive binding of enantiomers with protein.

污染土壤中多环芳烃的共代谢降解过程

The biodegradation of most PAHs with high molecular weight is carried out by means of cometabolism. The development of the theory about cometabolic degradation is reviewed in this paper, and the achievements on the cometabolic degradations of PAHs are also summarized. It is demonstrated that glucose, biphenyl, organic acids and mineral oil could be used as cometabolic substrate to enhance the degradation rate of PAHs, and there are complex interactions in the microbiological degradation process among different PAHs. Some low molecular PAHs could serve as cometabolic substrate, which could also be used to enhance the transformation rate of high molecular weight recalcitrant PAHs. To achieve the cometabolic degradation of the PAHs in the soils, the following problems must be solved: the screening out of efficient degradative strains, the selection of the appropriate cometabolic substrate, the addition of surfactant if necessary and the optimization of operational parameters with the contaminated soils. These problems are the important parts of the project for the cometabolic degradation of PAHs in the soils.

Bioactive, Luminescent and Mesoporous Europium-doped Hydroxyapatite as a Drug Carrier

Bioactive, luminescent and mesoporous europium-doped hydroxyapatite (Eu:HAp) was successfully prepared through a simple one-step route using cationic surfactant as template. The obtained multifunctional hydroxyapatite was performed as a drug delivery carrier to investigate the drug storage/release properties using ibuprofen (IBU) as a model drug

Sulfonated poly(ether ether ketone)/clay-SO3H hybrid proton exchange membranes for direct methanol fuel cells Journal of Power Sources

A new type of sulfonated clay (clay-SO3H) was prepared by the ion exchange method with the sulfanilic acid as the surfactant agent. The grafted amount of sulfanilic acid in clay-SO3H was 51.8 mequiv. (100 g)(-1), which was measured by thermogravimetric analysis (TGA). Sulfonated poly(ether ether ketone) (SPEEK)/clay-SO3H hybrid membranes which composed of SPEEK and different weight contents of clay-SO3H, were prepared by a solution casting and evaporation method. For comparison, the SPEEK/clay hybrid membranes were produced with the same method.

Preparation of nanoparticles of bipyridineruthenium and silicotungstate and application as electrochemiluminescence sensor

The novel nanoparticles, [Ru(bPY)(3)](2)SiW12O40 center dot 2H(2)O(2) were firstly synthesized and characterized by elemental analysis, IR, and TEM. The nanoparticles were used to fabricate a chemically modified carbon paste electrode (CPE) by dispersing nanoparticles and graphite powder in silicone grease. Thus-prepared CPE shows bifunctional electrocatalytic activities towards the reduction of nitrite and the oxidation of oxalate, and exhibits sensitive electrochemiluminescence (ECL).

Preparation and properties of polyether pentaerythritol mono-maleate grafted linear low density polyethylene by reactive extrusion

A reactive type nonionic surfactant, polyether pentaerythritol mono-maleate (PPMM) was synthesized in our laboratory. PPMM was adopted as functionalizing monomer and grafted onto linear low density polyethylene (LLDPE) with a melt reactive extrusion procedure. FT-IR was used to characterize the formation of grafting copolymer and evaluate their degree of grafting. The effects of monomer concentration, reaction temperature and screw run speed on the degree of grafting were studied systematically. Isothermal crystallization kinetics of LLDPE and LLDPE-g-PPMM samples was carried out using DSC.

Synthesis and Luminescence Properties of CdS Nanoparticles

CdS nanoparticles were successfully prepared by polyol method with PVP-K30 as a surfactant. The microstructure, size and morphology of the products were investigated in detail by XRD, TEM and SEM. The results indicate that uniform CdS nanospheres were achieved. Photoluminescence properties of the resulted nanoparticles (S1 and S3) were investigated, and the results indicate that the CdS nanoparticles could be used as a potential blue light emitting material.

Synthesis and characterization of 1D Co/CoFe2O4 composites with tunable morphologies

1D Co/CoFe2O4 composites with tunable morphologies were fabricated by a facile solvothermal route in the presence of a surfactant poly(vinylpyrrolidone) (PVP); they may be very attractive for potential applications because of their outstanding soft magnetism.

Blue-light emission of mesoporous SBA-15 covalently bonded with carbazole chromophore

Much attention has been paid to carbazole derivatives for their potential applications as optical materials. For the first time, the blue-light-emitting carbazole chromophore has been covalently bonded to the ordered mesoporous SBA-15 (The resultant hybrid mesoporous materials are denoted as carbazole-SBA-15) by co-condensation of tetraethoxysilane (TEOS) and prepared compound 3-[N-3-(triethoxyilyl)propyl]ureyl-9-ethyl-carbazole (denoted as carbazole-Si) in the presence of Pluronic P123 surfactant. The results of H-1 NMR and Fourier transform infrared (FTIR) reveal that carbazole-Si has been successfully synthesized.

Surface-modified Nafion membranes with mesoporous SiO2 layers via a facile dip-coating approach for direct methanol fuel cells

In this study. Nafion (R) 117 membrane is surface-modified with mesoporous silica layers through in situ surfactant-templated sol-gel reaction. The reaction makes use of tetraethyl orthosilicate (TEOS) under acidic condition via dip-coating technique on both sides. Scanning electron microscopy (SEM), Fourier transformation infrared (FTIR), and thermogravimetric analysis (TGA) are employed to characterize the resultant membranes. Proton conductivity and methanol permeability of the membranes are also studied.

Hydrothermal synthesis and photoluminescent properties of stacked indium sulfide superstructures

Unusual hierarchical stacked superstructures of cubic beta-In2S3 were fabricated via a facile hydrothermal process in the presence of a surfactant cetyltrimethylammonium bromide CTAB; the 3D superstructures were developed by helical propagation of surface steps from microflakes of 10-20 nm thickness.

Unique electrochemiluminescence behavior of Ru(bpy)(3)(2+) in a gold/Nafion/Ru(bpy)(3)(2+) composite

The unique electrochemiluminescence (ECL) behavior of tris(bipyridine) ruthenium(II) (Ru(bpy)(3)(2+) immobilized in a gold/Nafion/Ru(bpy)(3)(2+) composite material was investigated. In this composite, the Ru(bpy)(3)(2+) ECL was found mainly occurred at 0-0.4 V during the cathodic scan process and the ECL peak was at about 0.1 V, which was quite different to the reported Ru(bpy)(3)(2+) ECL. Similar to the generally observed Ru(bpy)(3)(2+) ECL, the present ECL also could be enhanced by tri-n-propylarnine (TPA). It is also unique that in the presence of TPA, another ECL peak at about 0.38 V occurred.

Simple Electrochemical Route to Nanofiber Junctions and Dendrites of Conducting Polymer

We first report a simple and rapid electrochemical approach to synthesize novel nanofiber junctions and dendrites of conducting poly(o-phenylenediamine) without any surfactant or template. Through controlling some parameters such as the time and potential of electrodeposition and concentration of the reactant, nanofiber junctions and dendrites of conducting polymer can be easily obtained on the solid surface.

Microchip Micellar Electrokinetic Chromatography Based on One Functionalized Ionic Liquid and Its Excellent Performance on Proteins Separation

Herein, one water-soluble functionalized ionic liquid (IL), 1-butyl-3-methylimidazolium dodecanesulfonate (BAS), was designed, investigated and successfully applied to microchip micellar electrokinetic chromatography (MEKC) construction. It possessed the properties of both IL and surfactant. A fairly stable pH value similar to 7.4, which was fit to pH values of general biological buffers, was nicely placed at the optimum concentration of 20 mM BAS solution. While applying BAS solution as running buffer in poly(dimethylsiloxane) (PDMS) microfluidic systems, significantly enhanced electroosmotic flow (8-fold) and resolutions between analytes were obtained than that using other supporting electrolytes or surfactants.