Emission profiling and UV induced variations in anthrone reactive carbohydrate content from traditional biomass sources in rural Bangladesh
摘要
Anthrone-reactive carbohydrates (ARCs), including levoglucosan and structurally related sugar derivatives, are recognized tracers of biomass combustion due to their exclusive origin from cellulose pyrolysis. This study characterizes ARC emissions from common biomass fuels in Bangladesh and examines their photochemical transformation under UV irradiation (254 nm). Controlled combustion experiments were conducted with jute wood, rice husk, straw, and coconut leaves, and ARCs were quantified using Fourier-transform infrared spectroscopy (FTIR) and the anthrone-sulfuric acid colorimetric method. FTIR spectra confirmed functional groups consistent with carbohydrate structures, supporting the presence of saccharide-like compounds in particulate emissions. Among the fuels, jute wood produced the highest ARC concentration (53.04 ± 0.66 mg m− 3), while coconut leaf yielded the lowest (17.90 ± 2.65 mg m− 3). UV irradiation increased ARC levels in all samples, with the largest relative rise observed for coconut leaf, indicating the role of photochemical processes in enhancing ARC detectability. A strong correlation (r = 0.93) between pre- and post-irradiation values suggests that precursor availability governs secondary ARC formation. Notably, no ARCs were detected in fossil fuel emissions, reaffirming their specificity as biomass-burning indicators. These results demonstrate that photochemical aging can significantly alter the quantification of biomass-derived markers, likely through fragmentation of complex residues into smaller anthrone-reactive species. Although the anthrone assay provides rapid detection, its limited specificity highlights the need for advanced analytical approaches such as gas chromatography mass spectrometry (GC–MS) for unambiguous levoglucosan measurement.