Techniques and application in comprehensive multidimensional gas chromatography - mass spectrometry.

Area of Science:

• Analytical Chemistry
• Chromatography

Background:

• Comprehensive two-dimensional gas chromatography (GC×GC) is well-established.
• The definition of comprehensive multidimensional gas chromatography (MDGC) requires further clarification, particularly regarding analysis time on the second dimension column.
• MDGC aims for complete sample analysis using at least two separation stages.

Purpose of the Study:

• To describe implementation protocols for comprehensive MDGC.
• To illustrate the MDGC approach using a crude oil sample.
• To highlight the enhanced separation capabilities of MDGC compared to GC×GC.

Main Methods:

• Development of MDGC protocols involving single or multiple injections.
• Utilizing two Deans switches (DS) and cryogenic trapping.
• Sequential heart-cut (H/C) events with incremental time steps for complete sample analysis (40 injections).

Main Results:

• Achieved independent retention in each chromatographic dimension for enhanced separation.
• Demonstrated higher peak capacity and resolution on the second dimension column compared to GC×GC.
• Tentatively identified chemical classes, including mono- and diaromatics, within the crude oil sample.

Conclusions:

• MDGC provides superior resolution and peak capacity for complex sample analysis.
• The presented MDGC protocol, incorporating DS and cryogenic trapping, is effective for detailed chemical classification.
• While retention indices have limited utility for petroleum hydrocarbons, MDGC facilitates structured grouping of chemical classes.