Chromatographic speed classification for liquid chromatography using average theoretical peak time (ATPT).

Background: The development of analytical techniques in the field of liquid chromatography has brought new frontiers in performance and analytical speed for the technique. The proper evaluation of the analytical boundaries achieved with those developments was not addressed in the literature, since different liquid chromatography (LC) techniques have not yet received any classification regarding their chromatographic speed. Defining chromatographic analysis speed based simply on analysis time is an outdated concept since it is sample and analyte-dependent.

Influence of acquisition rate on performance of fast comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry for coconut fiber bio-oil characterization.

Comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC/TOFMS) is used to characterize complex bio-oil samples because of the high peak capacity associated with the high acquisition rate and mass spectra deconvolution capability of TOFMS. A recent application of fast GC × GC for this type of analysis improved sample throughput while achieving the same peak capacity without the use of cryogenic liquids. This work evaluates the effect of the TOFMS data acquisition rate on the quality of the analytical information obtained by GC × GC/TOFMS.

Towards the determination of an equivalent standard column set between cryogenic and flow-modulated comprehensive two-dimensional gas chromatography.

This preliminary research is focused on the task of defining an equivalent standard column set between cryogenic and flow-modulation comprehensive two-dimensional gas chromatography (GC × GC) combined with mass spectrometry (MS). Cryogenic modulation (CM) was carried out by using a loop-type device, while the flow modulator used was a seven-port wafer chip, equipped with an external accumulation loop. Initially, a common low-polarity + mid-polarity CM GC × GC column set was selected (30 m × 0.

Dzyaloshinskii-Moriya Interaction and Hall Effects in the Skyrmion Phase of Mn(1-x) Fe(x)Ge.

We carry out density functional theory calculations which demonstrate that the electron dynamics in the Skyrmion phase of Fe-rich Mn_{1-x}Fe_{x}Ge alloys is governed by Berry phase physics. We observe that the magnitude of the Dzyaloshinskii-Moriya interaction directly related to the mixed space-momentum Berry phases, changes sign and magnitude with concentration x in direct correlation with the data of Shibata et al. [Nat.

Preliminary studies of bio-oil from fast pyrolysis of coconut fibers.

This work studied fast pyrolysis as a way to use the residual fiber obtained from the shells of coconut ( Cocos nucifera L. var. Dwarf, from Aracaju, northeastern Brazil).