The haze episodes that occurred in Malaysia in September-October 1991, August-October 1994 and September-October 1997 have been attributed to suspended smoke particulate matter from biomass burning in southern Sumatra and Kalimantan, Indonesia. In the present study, polar organic compounds in aerosol particulate matter from Malaysia are converted to their trimethylsilyl derivatives and analyzed by gas chromatography-mass spectrometry in order to better assess the contribution of the biomass burning component during the haze episodes. On the basis of this analysis, levoglucosan was found to be the most abundant organic compound detected in almost all samples. The monosaccharides, alpha- and beta-mannose, the lignin breakdown products, vanillic and syringic acids and the minor steroids, cholesterol and beta-sitosterol were also present in some samples. The presence of the tracers from smoke overwhelmed the typical signatures of emissions from traffic and other anthropogenic activities in the urban areas.
Three short sediment cores from inner continental shelf of the southern South China Sea (5-50 km) off Terengganu were analyzed for lipid contents (i.e., homologous aliphatic compounds and sterols) using gas chromatography-mass spectrometry. The concentrations of the total aliphatic hydrocarbons (TAHs) ranged from 0.152 to 6.91 μg/g dry weight. The n-alkane distribution was from nC₁₃ to nC₃₆, with a carbon preference index (CPI₁₃₋₃₅) from 1.08 to 4.28 and a carbon number maximum (Cmax), depending on a sample, at 31 or 18. In addition, a strong odd-to-even carbon number predominance was observed in nC₂₅-nC₃₅ range. The distribution of the n-alkanoic acids and n-alkanols in all samples exhibited an even-to-odd carbon number predominance and ranged from C₁₀ to C₂₆ and from C₁₂ to C₃₄, respectively. The n-alkanols were dominated by the long-chain homologs with Cmax at 22; on the other hand, the n-alkanoic acid distributions showed a predominance of short-chain homologs with a Cmax at 16. The total sterol concentrations ranged from 0.41 to 3.57 μg/g dry weight. Cholesterol was most abundant at the offshore stations, whereas sitosterol was dominant at near-shore station. Pentacyclic triterpenoids such as friedelin and taraxerol α- and β-amyrins, which are known biomarkers for higher plants, were detected at all stations with a dilution trend offshore. In conclusion, the marine sediments off southern Terengganu can still be considered uncontaminated, where the compound sources are biogenic from terrestrial plants superimposed with a marine productivity input.