title: Free radical EPR spectroscopy analysis using blind source separation.
abstract: In this paper, we propose a novel approach for electron paramagnetic resonance (EPR) mixture spectra analysis based on blind source separation (BSS) technique. EPR spectrum of a free radical is often superimposed by overlapping spectra of other species. It is important and challenging to accurately identify and quantify the 'pure' spectra from such mixtures. In this study, an automated BSS method implementing independent component analysis is used to extract the components from mixed EPR spectra that contain overlapping components of different paramagnetic centers. To apply this method, there is no requirement to know the component spectra or the number of components in advance. The method is applied to analyze free radical EPR spectra which are collected from standard chemical system, cultured cell suspense, and ex vivo rat kidneys by spin trapping EPR technique. Results show that the BSS method proposed here is capable of identifying the component EPR spectra from mixtures with unknown compositions. The BSS technique can offer powerful aids in resolving spectral overlapping problems in general EPR spectroscopy analysis.
authors.affiliation: Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong.
authors.forename: J Y
authors.initials: JY
authors.lastname: Ren
authors.forename: C Q
authors.initials: CQ
authors.lastname: Chang
authors.forename: P C W
authors.initials: PC
authors.lastname: Fung
authors.forename: J G
authors.initials: JG
authors.lastname: Shen
authors.forename: F H Y
authors.initials: FH
authors.lastname: Chan
mesh_terms: D000465:Algorithms; D000818:Animals; D016466:CHO Cells / Q000737:chemistry; D006224:Cricetinae; D003412:Cricetulus; D003497:Cyclic N-Oxides / Q000032:analysis / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005609:Free Radicals / Q000032:analysis / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000032:analysis / Q000737:chemistry; D007668:Kidney / Q000737:chemistry; D009569:Nitric Oxide / Q000032:analysis / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000032:analysis / Q000737:chemistry*; D012815:Signal Processing, Computer-Assisted; D012996:Solutions / Q000032:analysis / Q000737:chemistry*; D013481:Superoxides / Q000032:analysis / Q000737:chemistry
chemical_list: D003497:Cyclic N-Oxides; D005609:Free Radicals; D017382:Reactive Oxygen Species; D012996:Solutions; D013481:Superoxides; C098505:5-diethoxyphosphoryl-5-methyl-1-pyrroline N-oxide; D009569:Nitric Oxide; D017665:Hydroxyl Radical