Characterization of neutralized wood vinegar derived from durian wood (Durio zibethinus) and its prospect as pesticide in acidic soil

Abstract

Wood vinegar is a brown liquid by-product obtained from the carbonization process. Wood vinegar could limit the usage of wood vinegar as pesticide in acidic soil because of its acidity. This study aimed to determine the main organic and inorganic components in neutralized durian wood vinegar. Wood vinegar was made by pyrolisis of durian wood in the absence of oxygen with a temperature of 350, 450, and 550 °C for 2 hours. Before being analyzed, wood vinegar was neutralized with NaOH 25% to formulate the new friendly pesticide in an agricultural field. Characterization for acidity was by pH meter; organic compounds were using GC-MS; inorganic compounds were using AAS. The result showed that both neutralized wood vinegar and acidic wood vinegar indicated groups of organic acids, phenol and carbonyl compounds, which were suspected as pesticides. The predominant component in acidic wood vinegar was guaiacol, while in neutralized wood vinegar was pyrocatechol. Both acidic and neutralized wood vinegar indicatively contained main inorganic elements such as sodium, calcium, potassium, magnesium, iron and zinc that could serve as a natural pesticide. Based on the analysis result of inorganic elements, there were significant differences between acidic and neutralized wood vinegar except for Ca.