Application of Sol-Gel Glass Immunoadsorbers for the Enrichment of Polycyclic Aromatic Hydrocarbons (PAHs) from Wet Precipitation

Recently, much progress has been made in developing and characterizing new types of immunoadsorbers that aim at a more selective and efficient enrichment of target analytes from complex environmental matrices. A bioceramic immunosorbent prepared by the incorporation of pyrene antibodies into glasses with the sol-gel glass technique was investigated for the direct extraction of polycyclic aromatic hydrocarbons from wet precipitation. The bioceramic support was filled into a specially manufactured adsorber cartridge and inserted in an outdoor rainwater collector. The capacity of the immunosorbent was affected neither by changes in the sample's pH value from 2-9, nor by increases in temperatures of up to 40°C. The maximum binding capacity of the immunosorbent did not significantly decrease over a 4-week field test at a rural area near Munich in the summer of 1998. The retention of the 16 EPA PAHs depended on the total amount of the analytes and their distribution in the sample, the capacity of the immunosorbent, and the affinity of the used antibody for the single compounds. In the field experiment only nanogram amounts of fluorene, phenanthrene, fluoranthene, pyrene, chrysene, benzo[b]fluoranthene, and benzo[a]pyrene were detected in the eluate of the immunoadsorber cartridge, which corresponds to concentrations clearly below 30 ng/l^-1 for these analytes in rainwater. According to these results, sol-gel glass immunosorbents also seem to be useful as selective adsorber materials in the field, although further studies are necessary.