PAH metabolites were derivatized
with 20 μL of N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA,
Fluke, Buchs, Switzerland). Extracts were analyzed by GC-MS to
quantify PAHs and their metabolites.

Quantification ofPAHsand Metabolites byGC-MS.

Analysis
byGC-MSwas performed with a gas chromatograph (HP-6890) coupled
to a 5973 C quadrupole mass spectrometer (Agilent Technologies,Massy,
France). The split/splitless injector was maintained at 280
C, and the
injection volume was 2 μL. The column used for separating PAHand their
metabolites was a OV-1 (Ohio-Valley) (30 m
0.25 mm inner diameter;
film thickness, 0.25 μm). The temperature gradient was 110
C (4.5min),
20
C/min until 160
C, 15
C/min until 300
C (10 min hold), and then
20
C/min until 320
C (2 min). Analyte ionization was performed by
electron ionization (70 eV), and signal acquisition was realized in the single
ion monitoring (SIM) mode. Separate analyte determination was
performed for parent PAHs and hydroxylated metabolites.