QSRR study of amino acids and lipids on the polar-embedded stationary phases according to the structural similarities

Bogusław Buszewski, Chair of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University in Torun & Interdisciplinary Center for Modern Technologies, Toruń, Poland (bbusz@chem.umk.pl)
Magdalena Skoczylas, Chair Of Environmental Chemistry And Bioanalytics, Faculty Of Chemistry, Nicolaus Copernicus University In Torun & Interdisciplinary Center For Modern Technologies, Toruń, Poland

In the case of separation techniques the evaluation of separation medium comprises an essential part of analytical methods improvement. Significant efforts have been made over the last few years to achieve stationary phases imitated natural matter (e.g. biological membrane) as well as endogenous compounds (e.g. amino acids). Specificity of chemically bonded ligands in the case of new materials enables receiving a so-called dedicated stationary phases. Moreover, structural similarity of the immobilized ligands with the desired group of analytes may determine the high selectivity of the prepared stationary phases. Therefore, the investigations in accordance with the “3S” assumption – similarity, selectivity, and specificity – allow the development of a new generation of separation materials.

The QSRR study comprises one of the approach that can give some insights into the separation mechanism occurring at the molecular level. The elementary objective of QSRR investigations is to determine a mathematical model that relates the analyte retention to physicochemical and structural parameters. Aside of molecular separation mechanism, the QSRR study allow to evaluating stationary phase properties, predicting retention for a new solutes, accelerating the phase selection of chromatographic method development etc.

The aim of this study was to develop prediction models using multiple linear regression that could accurately describe the retention behavior of a group of structurally related compounds – amino acids – on peptide-silica stationary phases operated in HILIC and – lipid compounds (phospholipids and sphingomyelin)  – on the polar-embedded stationary phases operated in HILIC and RP HPLC. The QSRR methodology has been applied according to the „3S” assumption - structural similarity of analytes and chemically bonded ligands. The research also aimed at using the prediction models to provide insights on the retention mechanism in the studied system. 

The derived mathematical models showed that the number of hydrogen bond acceptors is a main retention predictor for the peptide-silica columns, signifying that hydrogen bonding is crucial mechanism. On the other hand, the QSRR studies showed  that  the  dominant analyte  descriptor  influencing  retention  on the  alkyl-amine  stationary  phase  was  the  logarithm  of  the octanol-water  partition  coefficient.  For  the  phospho-diol  and  alkyl-amide  stationary  phases,  the  dominant  analyte  descriptor  influencing  retention  was  the  molar  volume  and  solvent  accessible  area  of  the analyte,  respectively.

Acknowledgement

This work was financially supported by the National Science Center (Poland) as a part of the PRELUDIUM 12 project No. 2016/23/N/ST4/00369.

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Abstract Reference & Short Personal Biography of Presenting Author

Professor Bogusław Buszewski is the head of the Chair of Environmental Chemistry & Bioanalytics at the Faculty of Chemistry, Nicolaus Copernicus University. He is also the president of the Central European Group for Separation Sciences and the chairmen of the Committee of Analytical Chemistry of Polish Academy of Sciences. Former, He was the president of the Polish Chemical Society and European Society for Separation Science. He was awarded by numerous national and international organizations. His main scientific interests are concerned with separation science including theoretical and practical aspects in chromatography and related techniques, adsorption, sample preparation, bianalytics and bioanalysis (metabolomics, proteomics, biomarkers), nanotechnology and chemometrics. He is authored or co-authored 15 books, patents and more than 567 scientific papers (over 10.000 citations, h= 46) and member of the editorial boards of 26 national and international journals in field of analytical chemistry and separation sciences.