Rapid quantification of polycyclic aromatic hydrocarbons in hydroxypropyl-β-cyclodextrin (HPCD) soil extracts by synchronous fluorescence spectroscopy (SFS)

Synchronous fluorescence spectroscopy (SFS) was directly applied to rapidly quantify selected polycyclic aromatic hydrocarbons (PAHs: benzo[a]pyrene and pyrene) in aqueous hydroxypropyl-β-cyclodextrin (HPCD) soil extract solutions from a variety of aged contaminated soils containing four different PAHs. The method was optimized and validated. The results show that SFS can be used to analyse benzo[a]pyrene and pyrene in HPCD based soil extracts with high sensitivity and selectivity. The linear calibration ranges were 4.0 × 10−6–1.0 × 10−3 mM for benzo[a]pyrene and 6.0 × 10−6–1.2 × 10−3 mM for pyrene in 10 mM HPCD aqueous solution alone. The detection limits according to the error propagation theory for benzo[a]pyrene and pyrene were 3.9 × 10−6 and 5.4 × 10−6 mM, respectively. A good agreement between SFS and HPLC was reached for both determinations of PAHs in HPCD alone and in soil HPCD extracts. Hence, SFS is a potential means to simplify the present non-exhaustive hydroxypropyl-β-cyclodextrin (HPCD)-based extraction technique for the evaluation of PAH bioavailability in soil.