Evaluation of multi-solvent size exclusion chromatography columns packed with sub-2 μm particles for the characterization of synthetic polymers.

With the recent development of small particle stationary-phases and dedicated instrumentation, the combination of size-exclusion chromatography (SEC) with ultra-high performance liquid chromatography (UHPLC) technology has been realized. It opened up a new polymer analysis technique called UHP-SEC. Although high resolution and fast analysis can be achieved, the multi-solvent suitability for a given column was limited to either organic or aqueous eluents.

Magnetization of 3-dimentional homochiral metal-organic frameworks for efficient and highly selective capture of phosphopeptides.

Enrichment of phosphopeptides based on various affinity probes prior to mass spectrometry detection is usually required due to the low abundance and low ionization efficiency of phosphopeptides. In this work, a 3-dimentional homochiral metal-organic frameworks (MOFs) was modified with magnetic nanoparticles using a facile method and then utilized for phosphopeptides capture with high efficiency and specificity. Based on magnetic solid phase extraction, a rapid and efficient method was developed and the whole enrichment procedure could be easily finished within 10min.

Metabolomics Approach Reveals Integrated Metabolic Network Associated with Serotonin Deficiency.

Serotonin is an important neurotransmitter that broadly participates in various biological processes. While serotonin deficiency has been associated with multiple pathological conditions such as depression, schizophrenia, Alzheimer's disease and Parkinson's disease, the serotonin-dependent mechanisms remain poorly understood. This study therefore aimed to identify novel biomarkers and metabolic pathways perturbed by serotonin deficiency using metabolomics approach in order to gain new metabolic insights into the serotonin deficiency-related molecular mechanisms.

Facile synthesis of magnetic homochiral metal-organic frameworks for "enantioselective fishing".

Magnetic functionalized homochiral metal-organic frameworks (MOFs) were prepared and applied to efficient enantioselective fishing of chiral drug intermediates. Under optimized conditions, the enantiomeric excess (ee) value as high as 85.2% was achieved for methyl phenyl sulfoxide (MPS) within 3 min.

[Analysis of tartrazine aluminum lake and sunset yellow aluminum lake in foods by capillary zone electrophoresis].

A novel analytical method for tartrazine aluminum lake and sunset yellow aluminum lake using capillary zone electrophoresis (CZE) was studied. The pigments contained in the color lakes were successfully separated from the aluminum matrix in the pre-treatment process, which included the following steps: dissolve the color lakes in 0.1 mol/L H2SO4, adjust the pH of the solution to 5.

Solid-phase extraction with the metal-organic framework MIL-101(Cr) combined with direct analysis in real time mass spectrometry for the fast analysis of triazine herbicides.

MIL-101(Cr) is an excellent metal-organic framework with high surface area and nanoscale cavities, making it promising in solid-phase extraction. Herein, we used MIL-101(Cr) as a solid-phase extraction packing material combined with fast detection of direct analysis in real time mass spectrometry (DART-MS) for the analysis of triazine herbicides. After systematic optimization of the operation parameters, including the gas temperature of DART, the moving speed of the 1D platform, solvent for desorption, amount of MIL-101(Cr) extraction time, eluent volume and salt concentration, this method can realize the simultaneous detection of five kinds of triazine herbicides.

Ambient mass spectrometry imaging: plasma assisted laser desorption ionization mass spectrometry imaging and its applications.

Mass spectrometry imaging (MSI) has been widely used in many research areas for the advantages of providing informative molecular distribution with high specificity. Among the recent progress, ambient MSI has attracted increasing interests owing to its characteristics of ambient, in situ, and nonpretreatment analysis. Here, we are presenting the ambient MSI for traditional Chinese medicines (TCMs) and authentication of work of art and documents using plasma assisted laser desorption ionization mass spectrometry (PALDI-MS).

Combination of dynamic pH junction with capillary electrophoresis-mass spectrometry for the determination of systemins in plant samples.

Systemin is an important group of plant peptide hormones participating in the regulation of plant defensive responses. An improved method, based on dynamic pH junction and capillary electrophoresis-quadrupole time-of-flight mass spectrometry, was developed for online enrichment and sensitive determination of trace systemins in plants. After optimization, the online enrichment factors for six target systemins ranged from 90- to 127-fold.

Applications of homochiral metal-organic frameworks in enantioselective adsorption and chromatography separation.

Chiral separation is of great importance for drug development, pharmacology, and biology. Chiral metal-organic frameworks (MOFs) is a new class of porous solid materials with high surface area, large pore size, high chemical stability, uniformly structured cavities, and the availability of modification. The excellent properties of MOFs have attracted intense interest to explore their performance and mechanism in chiral separation.

Graphene matrix for signal enhancement in ambient plasma assisted laser desorption ionization mass spectrometry.

In this work, the signal intensity of ambient plasma assisted laser desorption ionization mass spectrometry (PALDI-MS) was significantly increased with graphene as matrix. The graphene functions as a substrate to trap analytes, absorb energy from the visible laser irradiation and transfer energy to the analytes to facilitate the laser desorption process. The desorbed analytes are further ionized by helium plasma and analyzed by MS.

Automated and sensitive analysis of 28-epihomobrassinolide in Arabidopsis thaliana by on-line polymer monolith microextraction coupled to liquid chromatography-mass spectrometry.

By on-line solid phase microextraction with polymer monolith coupled to liquid chromatography-mass spectrometry (SPME-LC-MS), an automated and sensitive method for analysis of the endogenous 28-epihomobrassinolide (28-epihomoBR) in Arabidopsis thaliana was developed in this work. Firstly, a poly(methacrylic acid-co-ethylene dimethacrylate) (poly(MAA-co-EDMA)) monolith was prepared in the capillary and applied in in-tube SPME. Polyethylene glycol (PEG) was used as porogen to adjust the specific surface area and hydrophobicity of the target monolith to get satisfactory permeability, high mechanical strength and good stability.

Applications of ambient mass spectrometry in high-throughput screening.

The development of rapid screening and identification techniques is of great importance for drug discovery, doping control, forensic identification, food safety and quality control. Ambient mass spectrometry (AMS) allows rapid and direct analysis of various samples in open air with little sample preparation. Recently, its applications in high-throughput screening have been in rapid progress.

Online coupling of capillary electrophoresis with direct analysis in real time mass spectrometry.

The online coupling of capillary electrophoresis with ambient direct analysis in real time mass spectrometry (DART-MS) was realized by a coaxial tip interface. The analytes eluted from capillary electrophoresis (CE) were directly ionized by the metastable helium flux produced by DART and transferred into MS for the detection, with which the online separation and simultaneous detection were achieved. The CE-DART-MS can tolerate higher concentrations of detergents and salts than traditional CE-electrospray ionization (ESI)-MS and avoided the difficulties of collecting CE effluent and cleaning the interface, which simplified the experimental procedures and shortened the analysis time.

Normal phase LC coupled with direct analysis in real time MS for the chiral analysis of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and jasmonic acid.

Normal phase chiral LC (NPLC) has been proved to be powerful and efficient for chiral separation. However, the combination of NPLC with ESI or atmospheric pressure chemical ionization MS is restricted by the poor ionization efficiency and thermal fragmentations of analytes to some extent. Direct analysis in real time MS (DART-MS) is an ambient ionization technique that shows high ionization efficiency of the analytes in the normal phase mobile phase.