Limits of detection and quantification in comprehensive multidimensional separations. 1. A theoretical look

Area of Science:

• Analytical Chemistry
• Chromatography
• Spectroscopy

Background:

• Comprehensive multidimensional separations like GC×GC offer superior peak capacity and sensitivity for complex samples.
• These techniques have found broad applications in fields such as petroleum, environmental analysis, food science, and metabolomics.
• While beneficial, the modulation process in multidimensional chromatography can introduce measurement errors.

Purpose of the Study:

• To investigate the limits of quantification (LOQ) and detection (LOD) in comprehensive two-dimensional gas chromatography (GC×GC).
• To evaluate the impact of the two-step integration algorithm on these limits.
• To establish a framework for understanding and predicting LOQ and LOD based on experimental parameters.

Main Methods:

• Simulated chromatographic data to precisely control peak geometry and modulation phase.
• Analysis using the two-step integration algorithm.
• Results expressed as signal-to-noise ratio of the base peak (S/N(BP)) for broad applicability.

Main Results:

• The limit of detection (LOD) is influenced by the modulation ratio, ranging from S/N(BP) of 10-17.
• The limit of quantification (LOQ) depends on both modulation ratio and peak modulation phase.
• LOQ values varied from S/N(BP) of 10 to 50, contingent on experimental conditions.

Conclusions:

• The modulation ratio is a critical factor affecting LOD in GC×GC.
• Both modulation ratio and phase significantly influence LOQ, highlighting the need for careful experimental design.
• The S/N(BP) parameter provides a universal metric for quantifying performance in two-step integrated multidimensional chromatography.