title: Comparison of Continuous Wave and Rapid Scan X-band Electron Paramagnetic Resonance of Irradiated Clipped Fingernails.
abstract: X-band rapid scan electron paramagnetic resonance (EPR) measures the free radicals in irradiated clipped fingernails with higher signal-to-noise (S/N) and lower standard deviation of the signal amplitude for replicate measurements than does conventional continuous wave (CW) EPR in the same measurement time. For a clipped fingernail sample irradiated to 10 Gy and data acquisition time of 30 s with B1= 8.5 μT, the S/N for rapid scan is >2000 for the absorption spectrum and 1200 for the corresponding first derivative. The standard deviation for replicate measurements of signal amplitude is ~1%. For CW spectra, the S/N depends on the modulation amplitude. The CW signal has a first derivative peak-to-peak linewidth of 0.95 mT. For 30 s of CW acquisition time, the S/N was 30 for a conservative modulation amplitude of 0.2 mT and B1of 2.3 μT or 90 for a modulation amplitude of 0.4 mT and B1of 3.2 μT, which resulted in standard deviations of replicate measurements of 5% or 2%, respectively.
authors: Department of Chemistry and Biochemistry, University of Denver, Denver, CO 80208 USA.
authors: Hanan
authors: H
authors: Elajaili
authors: Department of Chemistry and Biochemistry, University of Denver, Denver, CO 80208 USA.
authors: Joseph
authors: J
authors: McPeak
authors: Naval Dosimetry Center, Bethesda, MD 20889-5614, USA.
authors: Alexander
authors: A
authors: Romanyukha
authors: Department of Chemistry and Biochemistry, University of Denver, Denver, CO 80208 USA.
authors: Priyanka
authors: P
authors: Aggarwal
authors: Department of Chemistry and Biochemistry, University of Denver, Denver, CO 80208 USA.
authors: Sandra S
authors: SS
authors: Eaton
authors: Department of Chemistry and Biochemistry, University of Denver, Denver, CO 80208 USA geaton@du.edu.
authors: Gareth R
authors: GR
authors: Eaton
mesh_terms: D001681:Biological Assay / Q000379:methods*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D066298:In Vitro Techniques; D008872:Microwaves; D009262:Nails / Q000737:chemistry* / Q000528:radiation effects*; D011874:Radiometry / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity