{"entity": "journal", "iuid": "5315aca53ff642f39bedd1d577ab3ef2", "timestamp": "2026-07-12T17:59:27.207Z", "links": {"self": {"href": "https://publications.scilifelab.se/journal/Journal%20of%20Chromatography%20A.json"}, "display": {"href": "https://publications.scilifelab.se/journal/Journal%20of%20Chromatography%20A"}}, "title": "Journal of Chromatography A", "issn": "1873-3778", "issn-l": "0021-9673", "publications_count": 3, "publications": [{"entity": "publication", "iuid": "fea1a7e762af45b685aa05c3f27307df", "links": {"self": {"href": "https://publications.scilifelab.se/publication/fea1a7e762af45b685aa05c3f27307df.json"}, "display": {"href": "https://publications.scilifelab.se/publication/fea1a7e762af45b685aa05c3f27307df"}}, "title": "Probing the retention mechanism of small hydrophilic molecules in hydrophilic interaction chromatography using saturation transfer difference nuclear magnetic resonance spectroscopy.", "authors": [{"family": "Shamshir", "given": "Adel", "initials": "A", "orcid": "0000-0002-4321-1639", "researcher": {"href": "https://publications.scilifelab.se/researcher/9593344e98f24fc48bd7efb2710e4b9f.json"}}, {"family": "Dinh", "given": "Ngoc Phuoc", "initials": "NP"}, {"family": "Jonsson", "given": "Tobias", "initials": "T"}, {"family": "Sparrman", "given": "Tobias", "initials": "T", "orcid": "0000-0002-4442-6367", "researcher": {"href": "https://publications.scilifelab.se/researcher/f0d27dbd2f014795b1f7aa164d34bada.json"}}, {"family": "Irgum", "given": "Knut", "initials": "K", "orcid": "0000-0003-3457-7564", "researcher": {"href": "https://publications.scilifelab.se/researcher/a53af6b9ed8a45748869319a088b15bf.json"}}], "type": "journal article", "published": "2020-07-19", "journal": {"title": "Journal of Chromatography A", "issn": "1873-3778", "volume": "1623", "issue": null, "pages": "461130", "issn-l": "0021-9673"}, "abstract": "The interactions and dynamic behavior of a select set of polar probe solutes have been investigated on three hydrophilic and polar commercial stationary phases using saturation transfer difference 1H nuclear magnetic resonance (STD-NMR) spectroscopy under magic angle spinning conditions. The stationary phases were equilibrated with a select set of polar solutes expected to show different interaction patterns in mixtures of deuterated acetonitrile and deuterium oxide, with ammonium acetate added to a total concentration that mimics typical eluent conditions for hydrophilic interaction chromatography (HILIC). The methylene groups of the stationary phases were selectively irradiated to saturate the ligand protons, at frequencies that minimized the overlaps with reporting protons in the test probes. During and after this radiation, the saturation rapidly spreads to all protons in the stationary phase by spin diffusion, and from those to probe protons in contact with the stationary phase. Probe protons that have been in close contact with the stationary phase and subsequently been released to the solution phase will have been more saturated due to a more efficient transfer of spin polarization by the nuclear Overhauser effect. They will therefore show a higher signal after processing of the data. Saturation transfers to protons in neutral and charged solutes could in some instances show clear orientation patterns of these solutes towards the stationary phases. The saturation profile of formamide and its N-methylated counterparts showed patterns that could be interpreted as oriented hydrogen bond interaction. From these studies, it is evident that the functional groups on the phase surface have a strong contribution to the selectivity in HILIC, and that the retention mechanism has a significant contribution from oriented interactions.", "doi": "10.1016/j.chroma.2020.461130", "pmid": "32505268", "labels": {"Swedish NMR Centre": "Collaborative"}, "xrefs": [{"db": "pii", "key": "S0021-9673(20)30359-9"}], "notes": [], "created": "2020-11-24T09:51:04.653Z", "modified": "2025-10-17T13:03:56.768Z"}, {"entity": "publication", "iuid": "9141765037d7488b988d103aee65853c", "links": {"self": {"href": "https://publications.scilifelab.se/publication/9141765037d7488b988d103aee65853c.json"}, "display": {"href": "https://publications.scilifelab.se/publication/9141765037d7488b988d103aee65853c"}}, "title": "Interaction of toluene with polar stationary phases under conditions typical of hydrophilic interaction chromatography probed by saturation transfer difference nuclear magnetic resonance spectroscopy.", "authors": [{"family": "Shamshir", "given": "Adel", "initials": "A", "orcid": "0000-0002-4321-1639", "researcher": {"href": "https://publications.scilifelab.se/researcher/9593344e98f24fc48bd7efb2710e4b9f.json"}}, {"family": "Dinh", "given": "Ngoc Phuoc", "initials": "NP"}, {"family": "Jonsson", "given": "Tobias", "initials": "T"}, {"family": "Sparrman", "given": "Tobias", "initials": "T", "orcid": "0000-0002-4442-6367", "researcher": {"href": "https://publications.scilifelab.se/researcher/f0d27dbd2f014795b1f7aa164d34bada.json"}}, {"family": "Ashiq", "given": "Muhammad Jamshaid", "initials": "MJ"}, {"family": "Irgum", "given": "Knut", "initials": "K", "orcid": "0000-0003-3457-7564", "researcher": {"href": "https://publications.scilifelab.se/researcher/a53af6b9ed8a45748869319a088b15bf.json"}}], "type": "journal article", "published": "2019-03-15", "journal": {"volume": "1588", "issn": "1873-3778", "issue": null, "pages": "58-67", "title": "Journal of Chromatography A", "issn-l": "0021-9673"}, "abstract": "Toluene has been used as void volume (zero retention) marker since the inception of hydrophilic interaction chromatography (HILIC), based on the assumption that its hydrophobicity should prevent it from interacting with stationary phases envisioned to be covered by relatively thick layers of water. Recent work has shown that the void volumes of partly water-swollen HILIC phases are not identical to the volumes probed by toluene, yet the compound is still ubiquitously used as void volume marker. As part of our investigations of the retention mechanisms in HILIC, we probed the extent to which toluene is capable of penetrating into the water-enriched layer and to interact with the functional groups of three commercially available hydrophilic and polar stationary phases with different charge properties and water-retaining abilities, using saturation transfer difference 1H nuclear magnetic resonance (STD-NMR) spectroscopy at high resolution magic angle spinning (HR-MAS) conditions. The test solutions were 1000 ppm of toluene in deuterated acetonitrile and water mixtures, with and without addition of ammonium acetate, in order to mimic a set of conditions typically encountered in HILIC separations. Interactions between toluene and the functional groups on the stationary phases were probed by equilibrating the phases with these eluent mimics and measuring the transfer of magnetization from stationary phase protons to the protons of toluene. Our results show that toluene is indeed capable of traversing the water-enriched layers of all the three tested phases and of interacting with protons that are tightly associated with the stationary phases.", "doi": "10.1016/j.chroma.2018.11.028", "pmid": "30704776", "labels": {"Swedish NMR Centre": "Collaborative"}, "xrefs": [{"db": "pii", "key": "S0021-9673(18)31427-4"}], "notes": [], "created": "2019-01-03T13:28:03.016Z", "modified": "2025-10-17T13:03:58.139Z"}, {"entity": "publication", "iuid": "7ca22d9ce1804e1091eafa311412cf2e", "links": {"self": {"href": "https://publications.scilifelab.se/publication/7ca22d9ce1804e1091eafa311412cf2e.json"}, "display": {"href": "https://publications.scilifelab.se/publication/7ca22d9ce1804e1091eafa311412cf2e"}}, "title": "Solid-phase extraction of the alcohol abuse biomarker phosphatidylethanol using newly synthesized polymeric sorbent materials containing quaternary heterocyclic groups.", "authors": [{"family": "Duarte", "given": "Mariana", "initials": "M"}, {"family": "Jagadeesan", "given": "Kishore Kumar", "initials": "KK"}, {"family": "Billing", "given": "Johan", "initials": "J"}, {"family": "Yilmaz", "given": "Ecevit", "initials": "E"}, {"family": "Laurell", "given": "Thomas", "initials": "T"}, {"family": "Ekstr\u00f6m", "given": "Simon", "initials": "S"}], "type": "journal article", "published": "2017-10-13", "journal": {"title": "Journal of Chromatography A", "issn": "1873-3778", "volume": "1519", "issue": null, "pages": "1-8", "issn-l": "0021-9673"}, "abstract": "Phosphatidylethanol (PEth) is an interesting biomarker finding increased use for detecting long term alcohol abuse with high specificity and sensitivity. Prior to detection, sample preparation is an unavoidable step in the work-flow of PEth analysis and new protocols may facilitate it. Solid-phase extraction (SPE) is a versatile sample preparation method widely spread in biomedical laboratories due to its simplicity of use and the possibility of automation. In this work, SPE was used for the first time to directly extract PEth from spiked human plasma and spiked human blood. A library of polymeric SPE materials with different surface functionalities was screened for PEth extraction in order to identify the surface characteristics that control PEth retention and recovery. The plasma samples were diluted 1:10 (v/v) in water and spiked at different concentrations ranging from 0.3 to 5\u03bcM. The library of SPE materials was then evaluated using the proposed SPE method and detection was done by LC-MS/MS. One SPE material efficiently retained and recovered PEth from spiked human plasma. With this insight, four new SPE materials were formulated and synthesized based on the surface characteristics of the best SPE material found in the first screening. These new materials were tested with spiked human blood, to better mimic a real clinical sample. All the newly synthetized materials outperformed the pre-existing commercially available materials. Recovery values for the new SPE materials were found between 29.5% and 48.6% for the extraction of PEth in spiked blood. A material based on quaternized 1-vinylimidazole with a poly(trimethylolpropane trimethacrylate) backbone was found suitable for PEth extraction in spiked blood showing the highest analyte recovery in this experiment, 48.6%\u00b16.4%.", "doi": "10.1016/j.chroma.2017.08.051", "pmid": "28890270", "labels": {"Structural Proteomics": "Service"}, "xrefs": [{"db": "pii", "key": "S0021-9673(17)31232-3"}], "notes": [], "created": "2020-01-27T10:07:24.181Z", "modified": "2021-06-21T15:05:29.496Z"}], "created": "2019-01-03T13:28:03.029Z", "modified": "2020-11-27T13:14:07.570Z"}