Chromatographic fingerprinting by comprehensive two-dimensional chromatography: Fundamentals and tools

Comprehensive two‐dimensional gas chromatography as a boosting technology in food‐omic investigations

“…The separation power of GC × GC is undoubtedly a key characteristic that leads to the production of highly detailed 2D chromatographic fingerprints with rationally ordered retention structures that open new and interesting perspectives for data processing, for example, group-type analyses [27][28][29], while increasing confident identification of unknowns [30]. For example, the appropriate combination of column dimensions, stationary phase chemistries, and modulation dynamics in rationalizing the retention logic of alkyl substituted pyrazines from roasted coffee was discussed by Ryan et al [31] and by Mondello et al [32].…”

“…When the high compositional complexity of processed food prevents the clear identification of component signatures, on both retention patterns and MS spectra, dedicated data processing tools could be of help. If homologues patterns are mutually overlapped, the selective extraction of diagnostic MS signatures from the third analytical dimension by scripting functions [27,28,45,46] enables effective isolation of individual components and classes accompanied by 2D visualization. Figure 4 shows pseudocolor images of whole dried milk volatiles extracted by dynamic headspace (HS) by means of polydimethylsiloxane trap (4a and 4b) or by HS sorptive extraction on a polydimethylsiloxane sorptive phase.…”

“…Thanks to the rapid and straightforward evolution of MDA platforms, more stable and informative systems are now readily available, offering opportunities to extend and improve the concept of fingerprinting [27]. 2D peak patterns generated by GC × GC, or by LC × LC, can conceptually be compared to human fingertips whose minutiae features (e.g., ridge endings and bifurcations) are exploited by fingerprint recognition technology for individuals' identification.…”

“…Chromatographic fingerprinting has the potential to give access to the higher levels of information encrypted in MDA data sets. Its fundamental concepts and tools have been recently reviewed [27].…”

“…The elements of this rational approach are visualized in Figure 1 together with their interrelation with food omics investigative goals. A detailed discussion of individual key elements is outside the scope of this contribution; readers interested in more recent advancements on data processing and data mining for "omics" areas might refer to recent reviews [9,[11][12][13][14].…”