2.1 Chemicals and materials
PAH calibrants were prepared from
NIST SRM 1647f (16 EPA PAH in
acetonitrile) purchased from Promochem (Wesel, Germany). Cyclohexane and
diethyl ether were picograde and obtained from Promochem. Surrogate
standard mixture PAH-Mix 9 was from Dr. Ehrestorfer (Augsburg, Germany)
and contained the deuterated 16 EPA-PAH in cyclohexane. Stir bar
sorptive extraction (SBSE) devices (polydimethylsiloxane, 10 mm x 0.5
mm) were obtained from Gerstel (Mülheim an der Ruhr, Germany). Orbo-1000
polyurethane foam (PU foam) cartridges (22 mm outer ∅ x 7.6 cm)
containing 0.022 g PU foam cm-3 and matching quartz
filters (3.5 mm ∅) were purchased from (Supleco, Mainz, Germany) and
received in amber glass bottles.