Reversed-phase and weak anion-exchange mixed-mode stationary phase for fast separation of medium-, long- and very long chain free fatty acids by ultra-high-performance liquid chromatography-high resolution mass spectrometry.

Two commercial stationary phases allowing both reversed phase mechanism and anion-exchange with different selectivity, i.e. CSH C and Atlantis PREMIER BEH C AX, were tested for the separation of a complex mixture of 21 fatty acids (FAs) encompassing saturated medium-, long- and very long chain FAs, unsaturated long and very long chain FAs, cis/trans isomers, and isomers of odd- and branched-chain FAs.

Electrospray ion mobility mass spectrometry of positively charged sodium bis[2-ethythexyl)sulfosuccinate aggregates.

Collision cross-sections (CCS) of positively singly and multiply charged aggregates of the surfactant sodium bis(2-ethylhexyl)sulfosuccinate (AOTNa) in the gas phase have been measured by quadrupole ion mobility time-of-flight mass spectrometry. Calibration of the observed drift times to the CCS of the AOTNa non-covalent aggregates was achieved by collecting, under the same experimental conditions, the drift times of a range of singly and multiply charged polyalanine peptides whose CCS had been obtained by conventional ion mobility spectrometry. Together with an obvious increase of the aggregate cross-section with the aggregation number, it was found that the aggregate cross-section increases with the charge state due to the sodium counterions steric effect and the augmented electrostatic repulsion.

Proteomic profiling of proliferating and differentiated neural mes-c-myc A1 cell line from mouse embryonic mesencephalon by LC-MS.

The proteomic profiling, by means of label-free qualitative and quantitative LC-MS analysis of proliferating/undifferentiated vs nonproliferating/differentiated mes-c-myc A1 cell line (A1), has been performed. A1 cells were generated from mouse embryonic central nervous system. The study was aimed at surveying the molecular changes following neural differentiation.