This paper describes a procedure for fractionating polynuclear aromatic compounds (PNAs) from complex matrices according to number of aromatic rings. The procedure uses cartridges packed with amino polar bonded phase packing materials to achieve chromatographic separation of the polynuclear aromatic compounds. Data are provided demonstrating the applicability of the approach for Isolating PNAs from complex matrices. This procedure Is compared to a fairly well-known solvent extraction scheme for the Isolation of PNAs. Finally, the utility of the approach Is further demonstrated by applying the method to an extract of air particulate sample acquired from an oil refinery In the Lake Charles, LA, area.

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The colorimetric method for determining residual atrazine levels in soil is compared with reverse phase high performance liquid chromatography (HPLC). The soil samples are extracted with water-acetonitrile (10 + 90) and the filtrate is partitioned with methylene chloride. For the colorimetric analysis the organic phase is filtered through activity V alumina, collected, and evaporated to dryness. The residue is dissolved first in ethyl ether, and then in water as the ether is removed. The atrazine solution is buffered (citric acid, pH 7.0) and heated with added pyridine. When the reaction is complete, the product is complexed with ethylcyanoacetate, and the solution absorbance is measured at 550 nm. The complex obeys Beer’s law and has a sensitivity of 230 ng for a 1% full scale deflection at 1 AUFS. For the HPLC method, the methylene chloride extract is dried, the chromatographic solvent is quantitatively added (either chloroform or methanol), and the solution is analyzed with a UV detector at 254 nm. Minimum amount detectable for a 1% full scale deflection is 5 ng at 0.01 AUFS. Soil background interferences were investigated for both methods, and buffering the pyridine-triazine reaction solution was the most efficient method for removing the background for colorimetry. The recovery efficiencies for the colorimetric and HPLC methods were 45.5 ± 3.8% and 94.4 ± 3.4%, respectively.

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