Since Philips initiated GC×GC research in 1991, numerous laboratories—including the author’s own—have participated in the research and development of comprehensive two-dimensional gas chromatography technology. Commercialization of the instrument was formally achieved in 1999. This instrument exhibits the following characteristics:
- High resolution and large peak capacity: Its peak capacity equals the product of the individual peak capacities of the two columns that compose it, while its resolution is the square root of the sum of the squares of the individual resolutions of the two columns.
- High sensitivity: It can be 20 to 50 times more sensitive than conventional one-dimensional gas chromatography.
- Short analysis time: Because samples are more easily separated, the total analysis time is 反而 shorter than that of one-dimensional gas chromatography.
- Greatly enhanced qualitative reliability: Three factors contribute to this: first, most target compounds and compound groups can be baseline-separated, reducing interference; second, peaks are separated into easily identifiable patterns; third, the position of a peak—relative to other members of the same family—remains stable in each run.
- Broad method coverage: Owing to the high peak capacity and excellent resolution provided by the system, a single method can cover tasks that previously required several ASTM methods.
GC×GC represents a breakthrough advancement in gas chromatography technology and will occupy an increasingly important position in the separation and analysis of complex systems. Typical examples of such complex samples include:
- Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), biphenyls, chloroalkanes, polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), pesticides and herbicides (e.g., toxaphene and polychlorinated triphenyls);
- Chemical products, group composition analysis of petroleum products, and detailed analysis of individual hydrocarbons;
- Essential oils, fragrances (e.g., polycyclic musk compounds), and edible oils;
- Separation of chiral substances in complex systems;
- Analysis of volatile compounds in traditional Chinese herbal medicines and flavor components in traditional famous Baijiu (Chinese liquor), etc.