Adsorption of acid dyes from aqueous solutions by the ethylenediamine-modified magnetic chitosan nanoparticles.

The adsorption characteristics of Acid Orange 7(AO7) and Acid Orange 10 (AO10) from aqueous solutions onto the ethylenediamine-modified magnetic chitosan nanoparticles (EMCN) have been investigated. The EMCN were essentially monodispersed and had a main particle size distribution of 15-40 nm and saturated magnetization of 25.6 emu/g.

Simultaneous removal of phenanthrene and lead from artificially contaminated soils with glycine-β-cyclodextrin.

Preparation of glycine-β-cyclodextrin (GCD) was carried out by the reaction of β-cyclodextrin with glycine in the presence of KOH and epichlorohydrin. The enhanced solubilization behavior of phenanthrene and lead carbonate by GCD was studied, and the desorption behavior of phenanthrene and lead from co-contaminated soil was also investigated. The results showed that GCD has obvious solubilization for phenanthrene and lead carbonate.

Tracing origins of complex pharmaceutical preparations using surface desorption atmospheric pressure chemical ionization mass spectrometry.

A novel strategy to trace the origins of commercial pharmaceutical products has been developed based on the direct chemical profiling of the pharmaceutical products by surface desorption atmospheric pressure chemical ionization mass spectrometry (DAPCI-MS). Besides the unambiguous identification of active drug components, various compounds present in the matrixes are simultaneously detected without sample pretreatment, providing valuable information for drug quality control and origin differentiation. Four sources of commercial amoxicillin products made by different manufacturers have been successfully differentiated.

Adsorption of platinum(IV) and palladium(II) from aqueous solution by magnetic cross-linking chitosan nanoparticles modified with ethylenediamine.

The adsorption characteristics of platinum(IV) and palladium(II) from aqueous solutions onto the ethylenediamine-modified magnetic chitosan nanoparticles (EMCN) have been investigated. The magnetic chitosan nanoparticles were prepared by adding the basic precipitant of NaOH solution into a W/O microemulsion system. The transmission electron microscope showed that the diameter of EMCN was from 15 to 40 nm.

Rapid analysis of aerosol drugs using nano extractive electrospray ionization tandem mass spectrometry.

Aerosol drugs dominate a significant share of pharmaceutical preparations on the market. A novel sensitive method utilizing nano extractive electrospray ionization mass spectrometry (nanoEESI-MS) has been developed for the rapid analysis of aerosol drug samples with quantitative information. Without any sample pretreatment, aerosol drugs were manually sprayed into the primary ion plume created by a nano electrospray emitter for direct ionization under ambient conditions.

Sampling analytes from cheese products for fast detection using neutral desorption extractive electrospray ionization mass spectrometry.

The development of analytical techniques suitable for sensitive, high-throughput, and nondestructive food analysis has been of increasing interest in recent years. In this study, mass-spectral fingerprints of various cheese products were rapidly recorded in the mass range of m/z 50-300 Da without any sample pretreatment, using neutral desorption extractive electrospray ionization mass spectrometry (ND-EESI-MS) in negative ion mode. The results demonstrate that both volatile and nonvolatile analytes on greasy cheese surfaces can be directly sampled by a neutral desorption gas beam.

Metal-organic framework (MOF): lanthanide(III)-doped approach for luminescence modulation and luminescent sensing.

A distinct method, lanthanide(III)-doped pathway is for the first time utilized to replace lanthanide(III) MOFs for the access of MOF-based luminescent sensing of metal ions. The research results revealed that this strategy is highly effective and displays several outstanding features.

Geometry-independent neutral desorption device for the sensitive EESI-MS detection of explosives on various surfaces.

A novel geometry-independent neutral desorption (GIND) device was successfully developed, which made neutral desorption (ND) sampling easier and more robust on virtually all types of surfaces. The GIND device features a small air-tight enclosure with fixed space between the ND gas emitter, the sample surface, and the sample collector. Besides easy fabrication and convenient use, this configuration facilitates efficient neutral sample transfer and results in high sensitivity by preventing material loss during the ND process.

Competitive adsorption of a phthalate esters mixture by chitosan bead and alpha-cyclodextrin-linked chitosan bead.

The competitive adsorption effect by chitosan bead and alpha-cyclodextrin-linked chitosan bead on a mixture of six phthalate esters (PAEs) was investigated. The adsorption efficiency of short-chain hydrophilic PAEs was reduced when long-chain hydrophobic PAEs co-existed in the solution. Moreover, the adsorption efficiency of adsorbents for PAE is correlated to the distribution ratio (Kd), which shows that the Kd of hydrophobic PAEs is higher than that of hydrophilic PAEs.

Fast quantitative detection of cocaine in beverages using nanoextractive electrospray ionization tandem mass spectrometry.

Without any sample pretreatment, effervescent beverage fluids were manually sprayed into the primary ion plume created by using a nanoelectrospray ionization source for direct ionization, and the analyte ions of interest were guided into an ion trap mass spectrometer for tandem mass analysis. Functional ingredients (e.g.

Extractive electrospray ionization mass spectrometry for sensitive detection of uranyl species in natural water samples.

Ambient mass spectrometry has been increasingly applied for sensitive detection of trace organic compounds present in complex matrixes. In the real world, detection of trace amounts of inorganic species, particularly with speciation information, is of great significances. Herein a method based on extractive electrospray ionization (EESI) tandem mass spectrometry (MS/MS) has been established for rapid detection of radioactive inorganic species in natural water samples.

Molecular origin of enhanced strength in the monofilament of syndiotactic polypropylene because of annealing: a micro-FTIR study.

The conformational and polymorphic transformations in the melt-spun monofilament of syndiotactic polypropylene upon annealing and subsequent stretching have been first explored by micro-FTIR studies. The results indicate that annealing of as-spun monofilament gives rise to an unusual increase in the molecular orientation of helical conformations in both amorphous phase and ordered crystals as a result of structural transitions of transplanar conformations to helical ones as well as mesophase to ordered crystals. The increased molecular orientation in the annealed monofilament is mainly responsible for the enhanced strength during stretching.

[Contrast study on natural radioactive nuclides contents of rice between Xiangshan uranium deposit area, Jiangxi and non-uranium depsoit area].

The contents of natural radioactive nuclides such as uranium and thorium in paddies were analyzed and compared by means of ICP-MS. Totally 14 paddy samples were distinguished into two groups and collected from two rice planting area. One group (12 paddy samples) was collected from the Xiangshan uranium deposit area, Jiangxi province; while the other group (2 samples) collected from non-uranium deposit suburban area of Fuzhou city, Jiangxi, as comparison samples.

Differentiation of dried sea cucumber products from different geographical areas by surface desorption atmospheric pressure chemical ionization mass spectrometry.

Without any sample pretreatment, mass spectral fingerprints of 486 dried sea cucumber slices were rapidly recorded in the mass range of m/z 50-800 by using surface desorption atmospheric pressure chemical ionization mass spectrometry (DAPCI-MS). A set of 162 individual sea cucumbers (Apostichopus japonicus Selenka) grown up in 3 different geographical regions (Weihai: 59 individuals, 177 slices; Yantai: 53 individuals, 159 slices; Dalian: 50 individuals, 150 slices;) in north China sea were successfully differentiated according to their habitats both by Principal Components Analysis (PCA) and Soft Independent Modeling of Class Analogy (SIMCA) of the mass spectral raw data, demonstrating that DAPCI-MS is a practically convenient tool for high-throughput differentiation of sea cucumber products. It has been found that the difference between the body wall tissue and the epidermal tissue is heavily dependent on the habitats.

Selective detection of diethylene glycol in toothpaste products using neutral desorption reactive extractive electrospray ionization tandem mass spectrometry.

A rapid, sensitive method based on neutral desorption (ND) reactive extractive electrospray ionization mass spectrometry (EESI-MS) has been established for the selective quantitative detection of diethylene glycol (DEG) in toothpaste products without any sample pretreatment. The sensitivity and specificity of DEG detection were enhanced by implementing selective ion/molecule reactions in the EESI process, featuring the EESI mass spectra with the characteristic signals of DEG. The method provided a low limit of detection (LOD) (approximately 0.

What can we learn from ambient ionization techniques?

Ambient mass spectrometry-mass spectrometric analysis with no or minimal effort for sample preparation-has experienced a very rapid development during the last 5 years, with many different methods now available for ionization. Here, we review its range of applications, the hurdles encountered for its quantitative use, and the proposed mechanisms for ion formation. Clearly, more effort needs to be put into investigation of matrix effects, into defining representative sampling of heterogeneous materials, and into understanding and controlling the underlying ionization mechanisms.

Extractive electrospray ionization mass spectrometry toward in situ analysis without sample pretreatment.

A homemade novel nanoextractive electrospray ionization (nanoEESI) source has been characterized for in situ mass spectrometric analysis of ambient samples without sample pretreatment. The primary ions generated using a nanospray emitter interact with the neutral sample plume created by manually nebulizing liquid samples, allowing production of the analyte ions in the spatial cross section of the nanoEESI source. The performance of nanoEESI is experimentally investigated by coupling the nanoEESI source to a commercial LTQ mass spectrometer for rapid analysis of various ambient samples using positive/negative ion detection modes.

Adsorption of platinum(IV) and palladium(II) from aqueous solution by thiourea-modified chitosan microspheres.

The chitosan microparticles were prepared using the inverse phase emulsion dispersion method and modified with thiourea (TCS). TCS was characterized by scanning electron microscope (SEM), the Fourier transform infrared (FT-IR) spectra, sulfur elemental analysis, specific surface area and pore diameter. The effects of various parameters, such as pH, contact time, initial concentration and temperature, on the adsorption of Pt(IV) and Pd(II) by TCS were investigated.

Micro-FTIR study of molecular orientation at crack tip in nylon 6/clay nanocomposite: insight into fracture mechanism.

A study on the mechanism for the degraded toughness in nylon 6/clay nanocomposite is explored in this article. Such a nanocomposite exhibits lower specific essential work of fracture we and specific nonessential work of fracture betawp than its pure nylon 6 counterpart, as revealed by essential work of fracture (EWF) measurements. Furthermore, the molecular orientation in a small region (20x20 microm2) ahead of crack tip, obtained from micro-FTIR measurements for the first time, is found to be lower in the nanocomposite during crack initiation and propagation.

Adsorption of uranium (VI) from aqueous solution onto cross-linked chitosan.

Cross-linked chitosan (CCTS) was synthesized by the reaction of chitosan with epichlorohydrin under alkaline conditions. Adsorption of uranium (VI) from aqueous solution onto cross-linked chitosan was investigated in a batch system. Adsorption isotherm and adsorption kinetic studies of uranium (VI) onto cross-linked chitosan were carried out.

Replacement of hazardous chromium impregnating agent from silver/copper/chromium-impregnated active carbon using triethylenediamine to remove hydrogen sulfide, trichloromethane, ammonia, and sulfur dioxide.

Activated carbon (AC) is widely used as an effective adsorbent in many applications, including industrial-scale air purification systems and air filter systems in gas masks. In general, ACs without chemical impregnation are good adsorbents of organic vapors but poor adsorbents of low-molecular-weight or polar gases such as chlorine, sulfur dioxide (SO2), formaldehyde, and ammonia (NH3). Impregnated ACs modified with metallic impregnating agents (ASC-carbons; e.

Detection of melamine in milk products by surface desorption atmospheric pressure chemical ionization mass spectrometry.

Without any sample pretreatment, trace amounts of melamine in various milk products were rapidly detected noting the characteristic fragments (i.e., m/z 110, 85, and 60) in the MS/MS spectrum of protonated melamine molecules (m/z 127) recorded by using surface desorption atmospheric pressure chemical ionization mass spectrometry.

Neutral desorption using a sealed enclosure to sample explosives on human skin for rapid detection by EESI-MS.

A novel air-tight neutral desorption enclosure has been fabricated to noninvasively sample low picograms of explosives 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetraazocine (HMX), triacetone triperoxide (TATP), and nitroglycerin (NG) from human skin using a neutral nitrogen gas beam. Without further sample pretreatment, the explosive mixtures collected from the skin surface were directly transported by a nitrogen carrier gas over a 4-m distance for sensitive detection and rapid identification by extractive electrospray ionization tandem mass spectrometry.

Dysprosium-catalyzed growth of single-walled carbon nanotube arrays on substrates.

In this letter, we report that dysprosium is an effective catalyst for single-walled carbon nanotubes (SWNTs) growth via a chemical vapor deposition (CVD) process for the first time. Horizontally superlong well-oriented SWNT arrays on SiO2/Si wafer can be fabricated by EtOH-CVD under suitable conditions. The structure and properties are characterized by scanning electron microscopy, transition electron microscopy, Raman spectroscopy and atomic force microscopy.