2.4 Quantification of PAH using GC-MS
PAH congener quantifications were performed on an Agilent 7890A gas
chromatograph (Agilent Technologies, Waldbronn, Germany) equipped with a
MPS2 autosampler including an automated tube exchange device (Gerstel,
Mülheim/Ruhr, Germany), a Gerstel thermal desorption unit (TDU)
including a TDU tray, a Gerstel CIS4 cold injection system, and a Select
PAH column (30 m x 0.25 mm 0.15 µm) from Agilent. The gas chromatograph
was coupled to an Agilent 5975C inert XL mass selective detector. The
TDU was run in the splitless mode and started at 30 °C (held for 1 min)
and was ramped with 12 °C min-1 to 300 °C. The TDU
transfer temperature was kept at 320 °C. The CIS4 was operated in the
solvent vent mode at 8.77 psi and a helium (5.0) vent flow of 60 mL
min-1. The GC oven program started at 70 °C (held for
1 min) and was ramped with 40 °C min-1 to 140 °C, then
ramped with 20 °C min-1 to 350 °C and held for 5 min.
Helium 5.0 was used as carrier gas with a constant flow of 1.0 mL
min-1. The CIS injector was run in the splitless mode,
the transfer line, the ion source, and the quadrupole were kept at
280 °C, 230 °C, and 150 °C, respectively. The detector was run in the
single ion monitoring mode (electron impact, 70 eV) using the fragments
and retention time windows listed in supplementary Table S1. For
calibration of PAH determinations in extracts from PU foams, quartz
filters, and PAH source material fourteen gravimetrically prepared
dilutions of NIST 1647f in toluene were injected via the CIS4 injector
into of the GC-MS system similar as likewise the processed extracts
(section 2.3). For details on the concentrations and the calibration
curves obtained by linear regression throughout with coefficients of
determination > 0.995 see supplementary Table S1. For
calibration of the SBSE analyses seven cleaned SBSE devices were spiked
with toluene solutions of NIST 1647f and submitted to the TDU via the
tube exchange device similar to the SBSE devices exposed for airborne
PAH sampling (supplementary Table S1).