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GC COLUMNS | GENERAL-PURPOSE COLUMNS
GCxGC
Figure 1: In a contour plot like this one showing clear determination of over 80 pesticides in marijuana, the x-axis represents the
primary column retention time and the y-axis represents the secondary column retention time. Peaks aligned along the y-axis
would coelute in one-dimensional GC, which is especially problematic if they cannot then be separated by MS.
GC_FF1205
Column: Rxi®-5Sil MS 30 m, 0.25 mm ID, 0.25 µm (cat.# 13623); Rtx®-200 1.3 m, 0.25 mm ID, 0.25 µm (cat.# 15020); Sample: Diluent: Toluene;Injection: Inj. Vol.: 1 µL splitless (hold 1 min); Liner:
Sky™ 4 mm single taper w/wool (cat.# 23303.1); Inj. Temp.: 250 °C; Purge Flow: 40 mL/min; Oven: Oven Temp.: Rxi®-5Sil MS: 80 °C (hold 1 min) to 310 °C at 5 °C/min; Rtx®-200: 85 °C (hold 1 min)
to 315 °C at 5 °C/min; Carrier Gas:He, corrected constant flow (2 mL/min); Modulation: Modulator Temp. Offset: 20 °C; Second Dimension Separation Time: 3 sec; Hot Pulse Time: 0.9 sec; Cool Time
between Stages: 0.6 sec; Detector:TOFMS; Transfer Line Temp.: 290 °C; Analyzer Type: TOF; Source Temp.: 225 °C; Electron Energy: 70 eV; Mass Defect: -20 mu/100 u; Solvent Delay Time: 5 min; Tune
Type: PFTBA; Ionization Mode: EI; Acquisition Range: 45-550 amu; Spectral Acquisition Rate: 100 spectra/sec; Instrument: LECO Pegasus 4D GCxGC-TOFMS; Notes: Rtx®-200 (cat.# 15020) is a 15 m
column. A 1.3 m section was used as the second dimension column.
For a peak list, visit and enter chromatogram GC_FF1205 in the search function.
Coelution in
one-dimensional GC!
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primary/secondary
column combination for
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