ESTUDOS AMBIENTAIS PARA AVALIAÇÃO DAS RESPOSTAS FISIOLÓGICAS DA ESPÉCIE RAPANEA FERRUGINEA SUBMETIDAS A DIFERENTES CONDIÇÕES DE INCIDÊNCIA SOLAR POR ESPECTROSCOPIA NO INFRAVERMELHO COM TRANSFORMADA DE FOURIER (FTIR-ATR)

Abstract

With the advances in technology, the use of computer programs has become increasingly present in scientific research. Fourier-transform infrared spectroscopy (FTIR-ATR) combined with computational analysis is an important technique used in environmental studies to characterize biological systems. This technique studies how the chemical bonds present in the molecules interact with the radiation in the infrared range of the electromagnetic spectrum (10^-6 to 10^-3m) turning into vibrational energy, graphically represented in the form of an infrared spectrum. This study aimed to qualitative and quantitative analysis of lignin, starch and chlorophyll in leaf of Rapanea ferruginea (common name: capororoca) subject to different conditions of sunlight. To establish the different conditions of sunlight were made four frames in wood lined with shading screen in percentages by 30%, 50%, 70% and 85% shading. The seedlings were divided into five groups, each group being arranged in a frame, except one that was willing to full sun (frameless). The sample collection was carried out after expiry of a month from the beginning of the experiment. The infrared spectra of the samples were obtained in the range 4.000 to 450cm^-1. The absorbance ratio between the aromatic ring of the absorption band (1.609cm^-1) C-N-C (1.159cm^-1) and C-O (1.034cm^-1) with the C-H stretching band (2.917cm^-1) were considered to determine the amounts of lignin, starch and chlorophyll, respectively. From the quantification of these three constituents, the most favorable condition for the development of the plant is 70% shading, followed by 50% shading, 30% shading, 85% shading and last is the full sun.