Measurements of mass attenuation coefficient, effective atomic number and electron density of some amino acids

Abstract

The mass attenuation coefficients of some amino acids, such as dl-aspartic acid-LR(C4H7NO4), l-glutamine (C4H10N2O3), creatine monohydrate LR(C4H9N3O2H2O), creatinine hydrochloride (C4H7N3O·HCl) l-asparagine monohydrate(C4H9N3O2H2O), l-methionine LR(C5H11NO2S), were measured at 122, 356, 511, 662, 1170, 1275 and 1330keV photon energies using a well-collimated narrow beam good geometry set-up. The gamma-rays were detected using NaI (Tl) scintillation detection system with a resolution of 0.101785 at 662keV. The attenuation coefficient data were then used to obtain the effective atomic numbers (Zeff), and effective electron densities (Neff) of amino acids. It was observed that the effective atomic number (Zeff) and effective electron densities (Neff) initially decrease and tend to be almost constant as a function of gamma-ray energy. Zeff and Neff experimental values showed good agreement with the theoretical values with less than 1% error for amino acids.