Comprehensive two-dimensional gas chromatography under low-pressure conditions

The analysis of thermally labile and high-boiling point compounds by gas chromatography (GC) can be a challenge. One technique to overcome these challenges is low-pressure GC, which uses the vacuum produced from the mass spectrometer and wide-bore columns to elute compounds at significantly lower temperatures. While GC-MS is a powerful technique, comprehensive two-dimensional gas chromatography (GC x GC), allows for resolution of compounds that would typically coelute using GC. In this study, a pesticide standard mixture (8270 MegaMix Standard) was analyzed using a conventional GC x GC-TOFMS configuration (0.25 mm inner diameter (i.d.) to a 0.18 mm i.d. column) and low-pressure GC x GC-TOFMS configuration (0.53 mm i.d. to a 0.53 mm i.d. column). Elution temperatures, sensitivity, and peak capacity were investigated for both configurations. Compounds eluted an average of 30 & DEG;C less on the lowpressure GC x GC-TOFMS configuration compared to the conventional GC x GC-TOFMS configuration. Moreover, the compounds were separated in-13 min on the low-pressure GC x GC-TOFMS as opposed to 33 min for conventional GC x GC-TOFMS. However, due to the wide-bore columns and faster runtimes the low-pressure GC x GC-TOFMS had a lower, & beta; corrected 2D peak capacity, nc,& beta;,2D, of 1260 while the conventional GC x GC-TOFMS was 3588. Interestingly, both configurations yielded a similar peak capacity production of 93 peaks/min and 107 peaks/min for low-pressure and conventional GC x GC-TOFMS, respectively. A "real world" sample of diesel fuel was tested on the low-pressure and conventional GC x GCTOFMS configurations and similar results were obtained compared to the pesticide standard mix except the peak capacity production of the low-pressure GC x GC-TOFMS configuration was higher than that of the conventional GC x GC-TOFMS method.& COPY; 2023 Elsevier B.V. All rights reserved.