Isolation of water-soluble organic matter from atmospheric aerosol

The development of a solid phase extraction (SPE) method is presented, whic h is capable of isolating approx. 60% of the water-soluble organic compound s from aerosol samples. The aqueous extracts of the filter samples were aci dified then passed through an SPE column. Four silica-based and two polymer ic reversed phase columns were tested and similar recoveries of the organic carbon were found. The isolated organic matter was nearly free from inorga nic ions, which are major constituents of atmospheric aerosol. This fractio n accounted for a major part of the UV absorption above 250 nm and fluoresc ence activity of the aerosol extract. The precision of the method was teste d by performing three parallel sample preparations with Oasis HLB columns. It was found that the relative standard deviation of the carbon content of the isolated organic matter was better than 7%, which indicated the reliabi lity of the method. In the atmospheric aerosol research the newly developed sample preparation method facilitates the physical and chemical characteri sation of water-soluble organic compounds without the interference of inorg anic constituents. (C) 2001 Elsevier Science BN. All rights reserved.