Comparison of Stir Bar Sorptive Extraction and Solid Phase Extraction as Enrichment Techniques in Combination with Column Liquid Chromatography for the Determination of Polycyclic Aromatic Hydrocarbons in Water Samples

Abstract

The commonly used solid-phase extraction (SPE) was compared with the recently developed stir bar sorptive extraction (SBSE) to determine EPA-PAHs from precipitation water samples. SPE was performed using C18 PAH-filled cartridges; magnetic stirring rods 10 mm long and coated with 0.5 mm (24 µL) polydimethylsiloxane were used for SBSE. Determination was performed by high performance liquid chromatography and fluorescence detection. The investigations were performed at a concentration level of 30 ng/L, adjusted to actual PAH concentration levels of precipitation water. The recoveries ranged between 54% (SBSE) and 20% (SPE) respectively and about 100%, while the standard deviation ( n = 5) varied in the range of 4.7-13.5% (SBSE) and 3.6-16.9% (SPE) except for the more volatile compounds acenaphthene and fluorene. The detection limits calculated were between 0.4 and 5.0 ng/L. Both techniques were applied to study the PAH contents of precipitation water of several polluted sites in the city of Halle (Saxony-Anhalt, Germany). The advantages and disadvantages of the methods used are discussed.