Resistively heated gas chromatography coupled to quadrupole mass spectrometry
The potential of fast temperature-programmed gas chromatography (GC) was studied by combining a resistively heated gas chromatograph and a quadrupole mass spectrometer (MS). An EZ Flash GC was used, which generates temperature ramps up to 1200 8/min and cools down from 300 to 508C in some 30 s; samples were injected via a conventional split/splitless injector in both injection modes. The combination of a short narrow-bore column (5 m60.1 mm ID), a high gas flow rate, and fast temperature programs typically decreased conventional analysis times of 30 min to about 3 min. The scan speed of the quadrupole mass spectrometer (16 spectra/s in the range m/z 50 -310) was found to be sufficient for a proper reconstruction of the chromatographic peaks, and good-quality mass spectra could be obtained. Six scans across a peak were sufficient for peak integration. The system was linear in the range of 0.01 -3 ng injected mass and detection limits for pesticides were in the range of 1 -25 pg in the full-scan and 0.1 -5 pg in the selected ion monitoring mode. Series of apple and mole liver extracts were analyzed to demonstrate the high sample throughput and suitability of EZ Flash GC for fast screening.