Silica, hybrid silica, hydride silica and non-silica stationary phases for liquid chromatography.

J Chromatogr Sci

Núcleo Biotecnológico, Universidade do Oeste de Santa Catarina, Rua Paese, 198, Bairro Universitário-Bloco K. Videira, SC CEP 89560-000, Brazil

Published: April 2015

Free silanols on the surface of silica are the "villains", which are responsible for detrimental interactions of those compounds and the stationary phase (i.e., bad peak shape, low efficiency) as well as low thermal and chemical stability. For these reasons, we began this review describing new silica and hybrid silica stationary phases, which have reduced and/or shielded silanols. At present, in liquid chromatography for the majority of analyses, reversed-phase liquid chromatography is the separation mode of choice. However, the needs for increased selectivity and increased retention of hydrophilic bases have substantially increased the interest in hydrophilic interaction chromatography (HILIC). Therefore, stationary phases and this mode of separation are discussed. Then, non-silica stationary phases (i.e., zirconium oxide, titanium oxide, alumina and porous graphitized carbon), which afford increased thermal and chemical stability and also selectivity different from those obtained with silica and hybrid silica, are discussed. In addition, the use of these materials in HILIC is also reviewed.

Download full-text PDF

Source
http://dx.doi.org/10.1093/chromsci/bmu090DOI Listing

Publication Analysis

Top Keywords

stationary phases
16
silica hybrid
12
hybrid silica
12
liquid chromatography
12
silica
8
non-silica stationary
8
thermal chemical
8
chemical stability
8
stationary
5
silica hydride
4

Similar Publications

Serving as a dedicated process analytical technology (PAT) tool for biomass monitoring and control, the capacitance probe, or dielectric spectroscopy, is showing great potential in robust pharmaceutical manufacturing, especially with the growing interest in integrated continuous bioprocessing. Despite its potential, challenges still exist in terms of its accuracy and applicability, particularly when it is used to monitor cells during stationary and decline phases. In this study, data pre-processing methods were first evaluated through cross-validation, where the first-order derivative emerged as the most effective method to diminish variability in prediction accuracy across different training datasets.

View Article and Find Full Text PDF

This work aims to provide a basis for the enhancement of fucoxanthin (FCX) and eicosapentaenoic acid (EPA) biosynthesis in the microalga Phaeodactylum tricornutum using metabolomics and computational biology. To achieve this, both targeted (UHPLC and GC-FID) and untargeted (FTIR and NMR) analyses were conducted throughout various stages of cell cultivation. Targeted analyses revealed that EPA concentrations peaked at the end of the logarithmic growth phase, while fucoxanthin levels remained consistent from the onset of this phase through to the stationary phase.

View Article and Find Full Text PDF

How do red foxes (Vulpes vulpes) explore their environment? Characteristics of movement patterns in time and space.

Mov Ecol

January 2025

Wildlife Research Unit Baden-Württemberg, LAZBW, Atzenberger Weg 99, 88326, Aulendorf, Germany.

Background: Many animals must adapt their movements to different conditions encountered during different life phases, such as when exploring extraterritorial areas for dispersal, foraging or breeding. To better understand how animals move in different movement phases, we asked whether movement patterns differ between one way directed movements, such as during the transient phase of dispersal or two way exploratory-like movements such as during extraterritorial excursions or stationary movements.

Methods: We GPS collared red foxes in a rural area in southern Germany between 2020 and 2023.

View Article and Find Full Text PDF

Background: Estimates of tick abundance and distribution are used to determine the risk of tick-host contact. Tick surveys provide estimates of distributions and relative abundance for species that remain stationary and wait for passing hosts (i.e.

View Article and Find Full Text PDF

Chimera states in a system of stationary and flying-through deterministic particles with an internal degree of freedom.

Chaos

January 2025

Department of Control Theory, Scientific and Educational Mathematical Center "Mathematics of Future Technologies", Nizhny Novgorod State University, Gagarin Av. 23, Nizhny Novgorod 603022, Russia.

We consider the effect of the emergence of chimera states in a system of coexisting stationary and flying-through in potential particles with an internal degree of freedom determined by the phase. All particles tend to an equilibrium state with a small number of potential wells, which leads to the emergence of a stationary chimera. An increase in the number of potential wells leads to the emergence of particles flying-through along the medium, the phases of which form a moving chimera.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!