Cryogenic sample eject system for electron paramagnetic resonance spectrometers

Karl Rieger; Joshua Hoy; Timothy J Keller; Thorsten Maly

doi:10.1016/j.jmr.2024.107823

Cryogenic sample eject system for electron paramagnetic resonance spectrometers

J Magn Reson. 2024 Dec 17:370:107823. doi: 10.1016/j.jmr.2024.107823. Online ahead of print.

Authors

Karl Rieger¹, Joshua Hoy¹, Timothy J Keller¹, Thorsten Maly²

Affiliations

¹ Bridge12 Magnetic Resonance, 11 Michigan Drive, Natick, MA 01760, USA.
² Bridge12 Magnetic Resonance, 11 Michigan Drive, Natick, MA 01760, USA. Electronic address: tmaly@bridge12.com.

PMID: 39708478
DOI: 10.1016/j.jmr.2024.107823

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 T_m 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_m times and the lower effective concentrations.

Keywords: Automation; DEER; EPR Spectroscopy; INSTRUMENTATION; PELDOR.