Physics Journal of the Indonesian Physical Society
STUDY ON PHYSICAL AND OPTICAL PROPERTIES OF ALPHA ALANINE - A RADIATION DOSIMETRY MATERIAL
Frida Ulfah Ermawati
Physics Dept. Surabaya State University, Ketintang Campus, Surabaya 60231, Indonesia
Crystal structures of L-, D- and DL-a-alanine are provided as part of the research on the radiation damages in organic compounds using electron spin resonance technique. Powder X-ray diffraction analysis yields the phase compositions, lattice parameters, and unit cell identification of the three samples. It is verified that the L-, D- and DL-a-alanine are belong to orthorhombic system with the space group of P212121 and the similar lattice parameters of a = 6.040, b = 12.353 and c = 5.789Å for the D- and L-a-alanine; and Pna21 with a = 12.041, b = 6.035 and c = 5.836 Å, for the DL-a-sample. The differentiation between the L- and D-alanine is provided by optical activity analysis. It is determined that at the experimental condition of [a]25°D (c = 8.3; H2O + 2mole dm-3 HCl), L-a-alanine solution that has counterclockwise rotation of the constituent atoms, rotated the plane-polarized light to clockwise seen by the observer; The D-solution, on the other hand, has the reverse behaviors. This ability is attributed to the asymmetric arrangements of the molecules of the systems.