Two-dimensional hyperfine sublevel correlation (2D-HYSCORE) spectra of the gamma-irradiated crystal of L-alanine were used to detect possible contribution of N-14 hyperfine splitting to the spectrum of stable radical centers at room temperature. The N-14 hyperfine and quadrupole tensors were evaluated and assigned to an abstracted NH3 molecule, which appeared as a product of the first stable radical formation. The obtained results have been discussed as potentially new elements in description of the environment of the first stable L-alanine radical in the crystal lattice. (c) 2005 Elsevier B.V. All rights reserved.