Characterization of phosphorus in the aerosol of a coastal atmosphere: Using a sequential extraction method

Particulate aerosol was sequentially extracted by citrate/dithionite/bicarbonate and acetic acid/sodium acetate buffers so as to isolate phosphorus associated with oxides/hydroxides (Fe-P) and Acet-P, respectively. Total phosphorus (TP) and total inorganic phosphorus (TIP) contents were analyzed separately and the difference between them used to calculate the organic phosphorus (OP) content. The difference between TIP and the sum of Fe-P and Acet-P was assumed to be the detrital apatite (Det-P). The results of this study indicate that phosphorus species show a clear monthly variability that is related to the source strengths of the crustal weathering and biological blooming in winter and spring, respectively. There are highly significant covariations between the TP, TIP and Det-P, which suggests that these derive from similar sources and share transport mechanisms. The percentage concentrations of OP show that phosphorus tends to be associated with organic particles in warm periods when biological activity is greatest.