A not-stop-flow online normal-/reversed-phase two-dimensional liquid chromatography-quadrupole time-of-flight mass spectrometry method for comprehensive lipid profiling of human plasma from atherosclerosis patients.

A not-stop-flow online two-dimensional (2D) liquid chromatography (LC) method was developed for comprehensive lipid profiling by coupling normal- and reversed-phase LC with quadrupole time-of-flight mass spectrometry (QToF-MS), which was then applied to separate and identify the lipid species in plasma, making its merits in quality and quantity of the detection of lipids. Total 540 endogenous lipid species from 17 classes were determined in human plasma, and the differences in lipid metabolism products in human plasma between atherosclerosis patients and control subjects were explored in detail. The limit of detections (LODs) of 19 validation standards could all reach ng/mL magnitude, and the RSDs of peak area and retention time ranged 0.

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).

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.

Lipid profiling of human plasma from peritoneal dialysis patients using an improved 2D (NP/RP) LC-QToF MS method.

An improved online two-dimensional liquid chromatography-quadrupole time-of-flight mass spectrometry (2D LC-QToF MS) system was developed for the lipid profiling of human plasma, in which different lipid classes were separated by the first dimensional normal-phase (NP) LC and different lipid molecular species were separated by the second dimensional reversed-phase (RP) LC. This 2D LC-QToF MS system was built based on a ten-port, two-position valve as the interface, the conditions of which had been optimized and discussed in detail. As two loops were used to trap and transfer the first dimensional elute to the second dimension separately, this new interface suppressed the sample band broadening in the first dimensional column, increased the recovery and repeatability of 2D LC interface, and offered the possibility for the realization of not-stop-flow NP/RP 2D LC system.

Computational identification of a new binding site in influenza virus hemagglutinin for membrane fusion inhibitors.

The influenza virus hemagglutinin is a potential drug target for antivirus treatment. A variety of membrane fusion inhibitors targeting hemagglutinin have been discovered, but the binding sites and modes, important for understanding membrane fusion and rational drug design, have not yet been elucidated. In this article, we investigated the possible hemagglutinin binding sites for the current membrane fusion inhibitors.

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.

Graphite-coated paper as substrate for high sensitivity analysis in ambient surface-assisted laser desorption/ionization mass spectrometry.

In this work, an extremely simple and quite sensitive mass spectrometric method termed ambient surface-assisted laser desorption/ionization mass spectrometry (ambient SALDI-MS) was developed to analyze different kinds of compounds, just using a piece of graphite-coated paper for the sample introduction. This provides great advantage in simplifying the analysis process. The method is quite easy to use, and there is no need to worry about the source of graphite, that is, the brands or the types of pencil.