SEPARATION OF PHENOLIC-COMPOUNDS FROM SUGARCANE BAGASSE PITH AND THEIR DETERMINATION BY HPLC

Three chromatographic techniques were compared to determine the solubilized phenolic compounds, from sugarcane bagasse pith pretreatment. Reverse phase gradient system I, was chosen as a technique to be evaluated in aromatic compounds determination, because it presented good selectivity, reproducibility and percent recovery of phenolic compounds. However, gradient system II, and ionic exchange, resulted in longer resolution time, even though they had good resolution and selectivity. The amount of aromatic compounds determined by reverse phase gradient elution, were in decreasing order: 4-hydroxycinnamic acid (p-coumaric acid), 4-hydroxy-3-methoxycinnamic acid (ferulic acid), 4-hydroxybenzaldehyde (p-hydroxybenzaldehyde methoxybenzaldehyde (vanillin), and 4-hydroxy-3-methoxybenzoic acid (vanillic acid). Reverse phase gradient system I, can be useful to identify and quantify the phenolic compounds solubilized in other lignocellulosic materials. From the experimental design 2(3) the most important effect on total phenolic compounds solubilization, were: alkali concentration, temperature and alkali-moisture content interaction. In addition, the maximum amount of these compounds were obtained at high levels of experimental conditions, that is; 10% NaOH (ODW), 50 degrees C of temperature, and 80% of moisture content.