ENHANCED SELECTIVITY AND SENSITIVITY OF COMPREHENSIVE 2D GC COMBINED WITH A NOVEL FAST TRIPLE-QUAD MASS SPECTROMETER

Comprehensive two-dimensional gas chromatography (GC×GC), combined with mass spectrometry (MS), is an extremely powerful three-dimensional technology, which has found use only over the last decade. Very narrow peaks are generated in GC×GC applications, and so MS systems must possess fast acquisition frequencies. For such a reason, low-resolution high-speed time-of-flight (ToF) systems have been the most popular choice in the field, followed by rapid-scanning single quadrupole (q) instruments. The main scopes of most such GC×GCToF MS and GC×GC-qMS applications, have been the quantitative and/or qualitative analysis of untargeted solutes. There has been only a low number of cases in which other MS-types have been employed, a fact related to their slow spectral production rates. The present investigation is focused on the use and first evaluation of a novel high-speed triple quadrupole (QqQ) mass spectrometer, in flow-modulated GC×GC applications. The QqQ MS instrument can be operated simultaneously in the full scan and multiple reaction monitoring (MRM) modes, under the high spectral production frequencies required for GC×GC quali/quantitative determinations. It will be shown that, in the same GC×GC-QqQ MS application, both full-scan spectra relative to unknown compounds, and MS-MS data relative to known ones, can be attained, killing two birds with one stone. Obviously, a great increase both in sensitivity and selectivity were attained in the MRM mode. GC×GC-QqQ MS applications on real-world food samples, containing contaminants at the sub-ppb level, will be illustrated and discussed.