Enhancement of GC–MS Signal for Environmental Pollutants via the Transient Matrix Effect

Abstract

Matrix effects in gas chromatography (GC) are typically regarded as an analytical drawback, as co-eluting compounds can distort analyte quantification. This study demonstrates that a transient matrix effect can be deliberately induced to enhance GC–MS sensitivity for environmental pollutants. Four classes of high-boiling protectants—alcohols, amines, carboxylic acids, and polyethylene glycols (PEGs)—were systematically evaluated for their ability to increase detector response for polycyclic aromatic hydrocarbons (PAHs), chlorophenols, and nitrophenols. The influence of protectant type, sample solvent, injector temperature, and initial column temperature on signal enhancement was investigated. Among all protectants, PEGs yielded the highest improvements, with average signal increases of 280% for PAHs and 380% for chlorophenols and nitrophenols. The transient nature of the effect was confirmed through alternating injections, ensuring no cumulative influence on subsequent analyses. Application of the QuEChERS method to water and soil samples showed comparable enhancements, with minimal interference from matrix components. Method validation for PEG-400 confirmed excellent linearity (R² > 0.998), two- to threefold lower LODs, and high precision (RSD < 4.3%), demonstrating robustness and reproducibility. Leveraging a controlled transient matrix effect, this approach achieves several-fold improvement in detection limits without altering chromatographic hardware, providing a simple and adaptable tool for trace-level environmental monitoring.