Simple EPR/Alanine Dosimeter for Medical Application

Morsy, Mohamed A.

doi:10.4236/ojrad.2012.24022

Cited by 3 publications

(3 citation statements)

References 19 publications

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“…The use of polycrystalline alanine powder (without additional processing) has also been investigated for dosimetry applications (Al-Karmi and Morsy 2008; Ciesielski et al 2003; Morsy 2012). The main advantage of using pure alanine powder as a dosimeter is that the background signals formed due to the impurities of the binder material are negligible, and as a result, do not significantly affect the pre dose EPR signals of the dosimeter.…”

Section: Introductionmentioning

confidence: 99%

A Practical Method for EPR Dosimetry Using Alanine Powder

et al. 2022

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This work investigates alanine powder, an inexpensive and versatile material compared to alanine pellets, as a standardized dosimeter for the alanine-EPR system using a Bruker EMX-Micro spectrometer. The feasibility of this method was investigated, and a calibration curve was produced using 40 dosimeters, which were prepared by tightly packing DL-alanine powder in polypropylene microcentrifuge tubes. The dosimeters were irradiated to doses ranging from 0.2–20 Gy using a 60Co source. A dosimeter handling and measurement protocol was established for all dosimeters. The dosimetric signal was evaluated by measuring the peak-to-peak height of the central resonance peak, and the dose response of alanine powder dosimeters showed a linear behavior in the investigated dose range with relative errors below 13%. Measurement repeatability and reproducibility were tested to show the errors associated with sample placement in the cavity and with the overall measurement method, with both tests showing relative errors below 7%. As an inexpensive material compared to pellet dosimeters, alanine powder has a strong potential to be used as a standardized material for radiation dosimetry applications. The scope of this work is to present an effective and comprehensive methodology with accompanying analysis scripts for dosimetry with alanine powder that is useful in a wide range of applications and dose requirements.

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Section: Introductionmentioning

confidence: 99%

A Practical Method for EPR Dosimetry Using Alanine Powder

et al. 2022

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“…Due to the growing interest in radical detection and identification, electron paramagnetic resonance (EPR) spectroscopy is uniquely suited as a technique for monitoring free radical kinetics. We have previously reported using EPR spectroscopy as an analytical tool for free radical intermediates generated by different oxidation processes such as the irradiation of alanine [ 19 ] and the chemical and electrochemical oxidations of active ingredients in drug formulations [ 20 , 21 ]. In this work, we report the investigation of the free radical reactions of anthracene in concentrated sulfuric acid using EPR spectroscopy, which can be seen as a model system for other PAHs.…”

Section: Introductionmentioning

confidence: 99%

Electron and proton magnetic resonance spectroscopic investigation of anthracene oxidation

Morsy

Kawde

Kamran

et al. 2021

Heliyon

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The work reports a method for monitoring anthracene radical-mediated oxidation reactions using electron paramagnetic resonance (EPR) spectroscopy. The formation of anthracene dimer product was well-defined using 1 H-NMR and 1 H-1 H correlation spectroscopy (COSY). Unrestricted 3-21G/B3LYP DFT was used to estimate radical hyperfine spacing (hfs), then to identify the characteristic EPR-spin transitions of anthracene radical intermediate. A detailed investigation of an anthracene oxidation reaction and its possible reaction mechanism in concentrated sulphuric acid is conducted as a model system for polyaromatic hydrocarbons. Peak-to-peak (p2p) intensities of selected EPR-spectral lines were used to evaluate anthracene's oxidation kinetic model. The findings showed that radical intermediate formation is a unimolecular autocatalytic process, dimerization is a pseudo-zeroorder reaction, and the latter is the rate-determining step with a half-life of 48 AE 2 min at 25.0 C.

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“…Irradiation induces the formation of irradiation-specific free radicals in the biological matrix as a function of total irradiation dose. Indeed, conventional alanine dosimeters are based on measurement of alanine radical using electron paramagnetic resonance (EPR) spectroscopy (Morsy, 2012).…”

Section: Introductionmentioning

confidence: 99%

An analysis of cellulose‐ and dextrose‐based radicals in sweet potatoes as irradiation markers

Tonyalı

Sommers

Cerić

et al. 2020

Journal of Food Science

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Dried sweet potatoes (SPs) are often irradiated for improved safety and shelf life. Formation of irradiation‐derived radicals was analyzed using electron paramagnetic resonance (EPR) spectroscopy. These irradiation‐specific radicals can be used to characterize the irradiation history of dry plant‐based foods containing cellulose and sugars. The signal characteristics (intensity and peak shape) were evaluated at different sample locations (skin and flesh), as a function of sample preparation method (grinding, sieving, and pelletizing). The signal intensity was quantified using a double integration method of the peaks based on the area under the curve. The sieving caused ca. 50% decrease in total signal intensity as compared to nonsieved samples due to loss of cellulose‐based radicals. The flesh of irradiated SP showed complex EPR spectra with multiple satellite peaks of cellulose radicals (333.5 and 338.8 mT) and split peak of dextrose radicals (337.4 mT); while skin spectra were distinctive of cellulose radicals. In this study, we demonstrated the effects of sample composition and preparation method on formation and analysis of irradiation‐specific radicals based on EPR. Practical Application In the last decade or so, there have been health concerns related to the consumption of irradiated pet food products. Electron paramagnetic resonance spectroscopy can be used to analyze the irradiation history of dry products containing cellulose and sugar, such as the popular dog treat dried sweet potatoes, to ensure the products were irradiated within safe limits. This work demonstrates that the formation of irradiation‐specific radicals is affected by the sample location (skin and flesh) and moisture content.

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Simple EPR/Alanine Dosimeter for Medical Application

Cited by 3 publications

References 19 publications

A Practical Method for EPR Dosimetry Using Alanine Powder

A Practical Method for EPR Dosimetry Using Alanine Powder

Electron and proton magnetic resonance spectroscopic investigation of anthracene oxidation

An analysis of cellulose‐ and dextrose‐based radicals in sweet potatoes as irradiation markers

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