Abstract
The standard sampling methods usually require external power and controller. The methods usually collected a small amount of discrete samples which were subsequently analyzed using standard methods. If the data meet the requirements of quality control and quality assurance, we can identify law-violating contaminating source in due time. However, the data can’t represent the normal pollution situation. For contaminant concentration varying with time, we need to prolong sampling time and increase sampling frequency to assist identifying the contaminating source at the price of heavier workload and higher expense. Similar problems are encountered when analyzing ultratrace contaminants, bioaccumulating and bioavailable toxic substances. Passive accumulation devices (PAD) are free of external power and human intervention. Polyurethane foam (PUF) disk passive air sampler (PAS) has been successfully applied to persistent organic pollutants (POPs) in air. This study we successfully quantified the wind effect by monitoring and classifying wind speeds into ranges. Our calculated concentrations of dioxin-like compounds for PUF disk PAS samples approach those determined by active air sampling (AAS) methods. The hierarchical cluster analysis (HCA) indicated the PUF disk PAS can determine congener profiles of PCDD/Fs in ambient air. We also clarified the kind of dioxin pollution sources in monitoring area: They are small incinerator, auxiliary fuel (wood shavings) and secondary copper/iron smelters at industrial area in Taiwan; traffic exhaust gas and outdoor burning at Southeast Asia with background level concentration. Diffusion Gradients in Thin-film (DGT) use diffusive gel to separate the resin layer from bulk solution. The metal ions diffusing through the diffusive gel, the diffusion coefficient in the gel and sampling tine could calculate labile metal ion concentration. We established diffusion coefficient of metal like Mn, Ni, Cu, In, Cd, Ga, Ba and Pb. About application to natural water like river and lake, DGT could calculate the labile Mn, Ni and Cu concentration approach those determined by active methods; the concentration grade and trend of Cd, Ga, Ba, Pb, Cr, Fe, Mo, Ag, As, Se and Sb.