Optimisation of QuEChERS Methodology for the Improvement of Matrix Effects for the Analysis of Adamussium colbecki

Filter-feeding bivalves, such as Adamussium colbecki, are widely employed in environmental biomonitoring due to their ability to accumulate pollutants from their surrounding habitats. Their limited mobility, broad spatial distribution, and tolerance to various environmental conditions make them ideal sentinel organisms [1]. However, the complexity of bivalve tissue poses a significant challenge in contaminant analysis. The high protein (10-18%) and lipid (2-10%) content in A. colbecki tissues can interfere with Electrospray Ionisation (ESI) and mass spectrometric detection, compromising the accuracy and precision of quantitative analysis [2,3]. Consequently, efficient sample preparation strategies are necessary to mitigate these interferences, ensuring minimal effects on the ionization process. The ideal matrix effect (ME%) value is 100%, with deviation indicating signal suppression or enhancement [3]. The QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) is one of the most widely used extraction method due to its cost, efficiency, reliability, and low solvent requirement [2,4,5]. In this study, the QuEChERS method was adapted and optimised for A. colbecki samples. A multivariate experimental design was implemented to optimise the extraction conditions. The Plackett-Burman screening approach identified solvent-to-sample ratio, PSA amount, shaking mode, and clean-up time as the most influential parameters. Being a qualitative variable, shaking mode was fixed, whereas the other variables were subsequently optimised using a Doehlert design, studying ME% and R% as responses. The final optimised conditions included 12 mL of solvent for 100 mg of A. colbecki tissue, 85 mg of PSA sorbent, and a 1-minute clean-up. The optimised method using high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS) analysis was validated and environmental samples collected during Antarctic campaigns in 2001, 2005, 2018, and 2019 were analysed. Application of the optimised QuEChERS protocol to A. colbecki environmental samples revealed ME% values near 100% across all validated analytes, which confirms that the method effectively removes matrix interferences. This study underlines the necessity of employing multivariate optimisation strategies to address matrix complexities of environmental biomonitoring species, highlighting the effectiveness of QuEChERS in improving ME.