The penetration of green sample-preparation techniques in comprehensive two-dimensional gas chromatography

This critical review focuses on the use and the penetration of green sample-preparation (GSP) methods in comprehensive two-dimensional gas chromatography (GC × GC). The first GSP GC × GC experiment (supercritical-fluid extraction) appeared in 1994, and, since then, there has been a relatively-moderate use of this combination. Specifically, one approach (solid-phase microextraction) has been exploited quite often, while all others very rarely, apart from solid-phase extraction, which often does not fully fit within the GSP category. As well as descriptions of significant GSP GC × GC applications, we explain this divergent tendency and describe possible future scenarios.