2.4. GC–(APCI)QTOFMS
The chromatographic analyses were performed using an Agilent
7890A gas chromatograph, equipped with an Agilent 7693
autosampler, coupled to a quadrupole/time-of-flight mass spectrometer,
Xevo G2 QTOFMS (Waters Corporation, Manchester,
UK), with APCI source. The GC separation was performed using a
fused silica HP-5MS capillary column with (30 m 0.25 mm ID;
film thickness 0.25 lm (J&W Scientific, Folsom, CA). The oven program
was set as follows: 40 C (3 min); 5 C/min to 160 C (1 min);
50 C/min to 300 C (2.2 min); total runtime 33 min. Injections of
1 lL of sample extracts were performed using pulsed splitless
mode (50 psi) at a temperature of 270 C with a pulse time of