Are Antarctic marine species contaminated? An Optimised QuEChERS Extraction followed by LC-MS/MS analysis for Emerging Pollutants

Emerging contaminants (ECs) definition encompasses a wide range of anthropogenic and naturally produced chemicals that, despite their ecological risks, remain largely unregulated [1,2]. These substances, including pesticides, pharmaceutical and personal care products (PPCPs), plasticisers, and hormones have been detected in various ecosystems worldwide [2]. Even Antarctica, once considered a pristine environment, has shown increasing signs of contamination due to long-range atmospheric transport (LTR) and local anthropogenic activities [2,3]. The accumulation of ECs in polar ecosystems is intensified by extreme environmental conditions, which inhibit degradation processes (3). Consequently, ECs can bioaccumulate in polar organisms potentially leading to mutagenicity, genotoxicity, and reproductive damage in various species [4]. Among Antarctic marine species, bivalves are widely used as bioindicators of marine pollution due to their filter-feeding behaviour and widespread distribution. In particular, the Antarctic scallop Adamussium colbecki has been recognised as a valuable sentinel species due to its widespread presence in near-shore environments and its key role in the Southern Ocean ecosystem [5]. However, the high lipid and protein content of their biological matrix presents analytical challenges in contaminant detection [6]. Therefore, an effective sample pretreatment strategy is essential to ensure reliable quantification of ECs. The QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction method, initially developed for pesticide analysis, offers a promising solution due to its efficiency, and adaptability to complex matrices [6]. This study optimised and validated a QuEChERS-based extraction protocol for ECs in A. colbecki, followed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis. A multivariate experimental design was employed to enhance extraction efficiency, with recovery rates (R%) and matrix effects (ME%) serving as key performance indicators. Initially, a Plackett-Burman screening design was used to evaluate the influence of variables including solvent/sample ratio, sorbent amount (PSA, C18), extraction and clean-up times, and agitation mode. The most statistically significant factors (solvent/sample ratio, quantity of PSA, and clean-up time) were then further optimised using a Doehlert response surface design, resulting in an improved protocol that demonstrated satisfactory R% (46–123%) and ME% (62–103%) for 18 selected ECs. The method was subsequently applied to other Antarctic species, including Sphaerotylus antarcticus, Odontaster validus, Trematomus bernacchii, and Laternula elliptica, with R% ranging from 42-143% and ME% from 62-108%, confirming its robustness across diverse biota. The method was finally applied to environmental samples collected during Antarctic expeditions from 2001 to 2022 and successfully identified trace levels of contaminants such as triclosan (TCS), perfluorooctanoic acid (PFOA), and octyl-dimethyl p-aminobenzoic acid (OD-PABA) in the samples. Furthermore, a suspect screening analysis (SSA) using high-resolution mass spectrometry (HR-MS) is currently being conducted to expand the scope of ECs identification in Antarctic biota’s tissue. This study represents the first validated application of QuEChERS for ECs analysis in Antarctic species, establishing a reliable and standardised approach for long-term environmental monitoring. The optimised method enhances the ability to extract and detect emerging contaminants, contributing to a more comprehensive understanding of EC distribution and its potential impacts on the Antarctic marine ecosystem. By facilitating a more thorough evaluation of ECs in Antarctic biota, this methodology contributes to the broader understanding of human-induced impacts on one of the world's most fragile and unique ecosystems.