One of the main problems related to chromatography of peptides concerns adverse interactions of their strong basic groups with free silanol groups of the silica based stationary phase. Influence of type and concentration of ion-pairing regents on peptide retention in reversed-phase high-performance liquid chromatography (RP-HPLC) systems has been discussed before. Here we present influence of these mobile phase additives on retention of some peptide standards in high-performance thin-layer chromatography (HPTLC) systems with C18 silica-based adsorbents. We prove, that due to different characteristic of adsorbents used in both techniques (RP HPLC and HPTLC), influence of ion-pairing reagents on retention of basic and/or amphoteric compounds also may be quite different. C18 silica-based HPTLC adsorbents provide more complex mechanism of retention and should be rather considered as mixed-mode adsorbents.
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http://dx.doi.org/10.1016/j.chroma.2016.02.065 | DOI Listing |
J Sep Sci
December 2024
Department of Chromatography and Mass Spectrometry, Institute of Horticulture, Dobele, Latvia.
Silica-based monoliths offer higher separation efficiency per unit pressure drop compared to particle-packed columns. Their application is limited by the commercial availability of different column chemistries. Pentafluorophenyl ligands enable hydrogen bonding, dipole-dipole, π-π, and hydrophobic interactions, facilitating the separation of various compounds.
View Article and Find Full Text PDFJ Chromatogr A
December 2024
Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany.
We performed multiscale simulations of analyte sorption and diffusion in hierarchical porosity models of monolithic silica columns for reversed-phase liquid chromatography to investigate how the mean mesopore size of the chromatographic bed and the analyte-specific interaction with the chromatographic interface influence the analyte diffusivity at various length scales. The reproduced experimental conditions comprised the retention of six analyte compounds of low to moderate solute polarity on a silica-based, endcapped, C stationary phase with water‒acetonitrile and water-methanol mobile phases whose elution strength was varied via the volumetric solvent ratio. Detailed information about the analyte-specific interfacial dynamics received from molecular dynamics simulations was incorporated through appropriate linker schemes into Brownian dynamics diffusion simulations in three hierarchical porosity models received from physical reconstructions of silica monoliths with a mean macropore size of 1.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China. Electronic address:
The release of algae-derived dissolved organic matter (ADOM) significantly increased in serious eutrophication waters, posing great threats to drinking water safety. Thus, the molecular composition decipherment is urgently in need. However, due to unsatisfactory pretreatment and ionization effects, the application of Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) on ADOM was limited.
View Article and Find Full Text PDFJ Chromatogr A
September 2024
State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China.
Anal Chem
June 2024
Manitoba Centre for Proteomics and Systems Biology, 799 JBRC, 715 McDermot Avenue, Winnipeg R3E 3P4, Canada.
Can reversed-phase peptide retention be the same for C8 and C18 columns? or increase for otherwise identical columns with a smaller surface area? Can replacing trifluoroacetic acid (TFA) with formic acid (FA) improve the peak shape? According to our common understanding of peptide chromatography, absolutely not. Surprisingly, a thorough comparison of the peptide separation selectivity of 100 and 120 Å fully porous C18 sorbents to maximize the performance of our in-house proteomics LC-MS/MS setup revealed an unexpectedly higher peptide retentivity for a wider pore packing material, despite it having a smaller surface area. Concurrently, the observed increase in peptide retention─which drives variation in separation selectivity between 100 and 120 Å pore size materials─was more pronounced for smaller peptides.
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