Organic Contaminants In Soil/Sediment As A Tracer For Pollution Sources

Abstract

In this study, soil and sediment samples from known sources (sewage treatment plants, chicken farms, paddy fields and palm oil plantations) were analyzed for selected organic compounds (polycyclic aromatic hydrocarbons (PAHs), chlorpyrifos, cypermethrin and sterols). Samples were extracted using pressurized liquid extraction (PLE) techniques. The data sets obtained were subjected to chemometric techniques namely cluster analysis (CA), discriminant analysis (DA) and principal component analysis (PCA). Based on CA, two clusters were generated; cluster 1 consisting of PAHs, chlorpyrifos and cypermethrin while cluster 2 consisting of coprostanol, cholesterol, stigmasterol, stigmastanol, and β- sitosterol. DA plot rendered clear discrimination between the samples from different sources of contaminations. PCA analysis, applied to the data sets resulted in four latent factors explaining 63.8% of the total variance. The varifactors obtained from PCA indicated that the parameters responsible for source variations are sterols (coprostanol, cholesterol, stigmasterol, i¢-sitosterol and stigmastanol), which are strongly correlated to sewage and chicken farm samples, PAHs (naphthalene, acenaphtene, pyrene, benzo[a]anthracene and benzo[a]pyrene) and pesticides (chlorpyrifos and cypermethrin) which are comparatively correlated to samples from agricultural activities (paddy fields and palm oil plantations). The application of chemometric on selected organic compounds provides useful and promising techniques in tracing sources of contaminants as well as to reduce the complexity of the data interaction without lost of much important information.