EXPLOIT THE POWER OF LC/SFC SELECTIVITY TO ENHANCE GC×GC CHARACTERIZATION OF COMPLEX MIXTURES USING HYPHENATED TECHNIQUES

The introduction of hyphenated chromatographic techniques has revealed the complexity of many apparently simple samples, prompting the development of multidimensional techniques to enhance separation power and unravel this complexity. In 1980, the first attempt to hyphenate LC and GC was presented. Since then, the technique has followed a winding path, never gaining the attention it deserved and even facing commercial discontinuation. Conversely, comprehensive two-dimensional GC (GC×GC) was introduced in 1991 and quickly garnered attention, spreading across various research fields.
Liquid chromatography (LC) fractionation coupled to comprehensive two-dimensional gas chromatography (GC×GC) represents a powerful multidimensional strategy for addressing the analytical challenges posed by highly complex samples. LC fractionation before GC×GC reduces sample complexity, minimizes column overload (especially when compounds with a broad span of dynamic ranges are present), and enables targeted investigation of chemically defined fractions, thereby maximizing the resolving power of the comprehensive system.
Renewed interest in LC-based fractionation coupled to GC×GC has been driven by regulatory demands, notably in the determination of mineral oil hydrocarbons (MOH) in food. In this context, LC fractionation has become a key preparative step to isolate MOSH and MOAH fractions before GC or GC×GC analysis. The hyphenated systems can achieve the robustness, repeatability, and throughput required for routine analysis. Beyond enhanced qualitative information, LC fractionation combined with GC×GC significantly reduces analytical uncertainty and quantification biasAlthough on of the most known application is on MOH analysis, it can span far beyond.
This presentation aims to highlight the benefits of LC pre-fractionation before GC or GC×GC-FID/MS determination. Moreover, the investigation on the selectivity and performance of less-explored LC column stationary phases will be presented to reveal sample complexity and enhance characterization reliability.