Karl Rieger, Joshua Hoy, Timothy J. Keller, Thorsten Maly
{"title":"Cryogenic sample eject system for electron paramagnetic resonance spectrometers","authors":"Karl Rieger, Joshua Hoy, Timothy J. Keller, Thorsten Maly","doi":"10.1016/j.jmr.2024.107823","DOIUrl":null,"url":null,"abstract":"<div><div>We present a fully automated cryogenic sample insertion and ejection system for use with low-temperature EPR probes. We show how the system can be implemented on a conventional EPR spectrometer and that ejection and insertion is reliably possible at temperatures down to 10 K. Furthermore, we investigate the glass properties of a 0.1 mM sample of TEMPO in d<sub>8</sub>-glycerol/D<sub>2</sub>O (25/75, v/v) by measuring the electron phase memory time T<sub>m</sub> in addition to determining the effective spin concentration from a PELDOR/DEER background trace. These experiments were done either using the sample eject system or samples that were manually flash frozen. We show that using the ejection system we can consistently obtain a better glass matrix as indicated by the longer T<sub>m</sub> times and the lower effective concentrations.</div></div>","PeriodicalId":16267,"journal":{"name":"Journal of magnetic resonance","volume":"370 ","pages":"Article 107823"},"PeriodicalIF":2.0000,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of magnetic resonance","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1090780724002076","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"BIOCHEMICAL RESEARCH METHODS","Score":null,"Total":0}
引用次数: 0
Abstract
We present a fully automated cryogenic sample insertion and ejection system for use with low-temperature EPR probes. We show how the system can be implemented on a conventional EPR spectrometer and that ejection and insertion is reliably possible at temperatures down to 10 K. Furthermore, we investigate the glass properties of a 0.1 mM sample of TEMPO in d8-glycerol/D2O (25/75, v/v) by measuring the electron phase memory time Tm in addition to determining the effective spin concentration from a PELDOR/DEER background trace. These experiments were done either using the sample eject system or samples that were manually flash frozen. We show that using the ejection system we can consistently obtain a better glass matrix as indicated by the longer Tm times and the lower effective concentrations.
期刊介绍:
The Journal of Magnetic Resonance presents original technical and scientific papers in all aspects of magnetic resonance, including nuclear magnetic resonance spectroscopy (NMR) of solids and liquids, electron spin/paramagnetic resonance (EPR), in vivo magnetic resonance imaging (MRI) and spectroscopy (MRS), nuclear quadrupole resonance (NQR) and magnetic resonance phenomena at nearly zero fields or in combination with optics. The Journal''s main aims include deepening the physical principles underlying all these spectroscopies, publishing significant theoretical and experimental results leading to spectral and spatial progress in these areas, and opening new MR-based applications in chemistry, biology and medicine. The Journal also seeks descriptions of novel apparatuses, new experimental protocols, and new procedures of data analysis and interpretation - including computational and quantum-mechanical methods - capable of advancing MR spectroscopy and imaging.