An Investigation of the Chemical Variability of Woody Peat by FT-IR Spectroscopy

Abstract

Woody peats from Indonesia and Malaysia were examined by FT-IR spectroscopy to observe the variation in degree of humification between peat types and among botanical components and matrix material within a peat type. Results of the FT-IR analysis showed significant changes occurring in the 1600 and 1000 cm−1 regions which are interpreted to represent lignin and lignocellulose, respectively. These components were considered to describe variations in degree of humification. Between peat types the intensity of the lignocellulose region decreased accordingly between fibric, hemic, and sapric samples. Within a sample, variations in the relative amount of lignocellulose in the three different size fractions of a sample were observed that could generally, but not always, be related to peat type. In all peat types the coarse material still contained some lignocellulosic component, whereas the finer fractions contained variably less to no lignocellulose. The lignin-dominated composition of the finer matrix material suggests that these peats are derived mainly from trees and woody vines with little input from herbaceous, less decay-resistant (cellulose-dominant) plant material.