2.5.2. GC-ITMS system
A Thermo Quest TRACE 2000 gas chromatograph fitted
with a splitless injector and a DB-5ms capillary column
(30 m × 0.25 mm i.d., 0.25m film thicknesses) was used to
confirm the identity of fungicides. It was coupled to a GCQ plus
ion trap mass spectrometer and equipped with a Xcalibur version
1.1 software. The injector was operated at 230 ◦C and the
sample (1L) was injected in splitless injection (splitless time
1 min) and the oven was programmed as follows: 70 ◦C (1min),
increased to 180 ◦C (30 ◦C/min), then to 190 ◦C (1.5 ◦C/min),
and finally to 310 ◦C (3 ◦C/min) and held for 5 min. The ion trap
mass spectrometer was operated in the electron ionization (EI)
mode at 70 eV. The ion source was set at 200 ◦C and the transfer
line at 275 ◦C. The acquisition scan mode is set at full scan (m/z
45–500).
2.5.3. HPLC-UV system
Famoxadone determination in field samples was also performed
with an HP 1100 liquid chromatograph, equipped
with a ternary-delivery system, a Model 1100 UV detector
and a Chemstation chromatography manager data acquisition
and processing system. The analytical column was an ODS
Hyperesil C18 column (250 mm × 2.1 mm i.d., 5,0m particle
size). The mobile phase was acetonitrile–water, delivered
at a flow 0.26 mL/min with a gradient composition, from
acetonitrile–water (55 + 45, v/v) for 5 min, to acetonitrile–water
(80:20) in 10 min and hold for 10 min. Finally a decrease at
acetonitrile–water (55:45) over 10 min, giving a total run time
35 min. Titan 2 HPLC Nylon membrane filters 0.2 m pore
size were used for filtering all samples before chromatographic
injection (20L). The column temperature was 30 ◦C and the
detection wavelengths at 210 nm.
2.6