From Ultrasonic to Moka-like Devices: A Critical Comparison of Extraction Strategies for Emerging Pollutants in Antarctic Marine Sediments

The analysis of marine sediments is a critical tool for evaluating the extent of anthropogenic impacts on aquatic environment. Marine sediments can accumulate various contaminants, with particular concern directed towards lipophilic compounds. These substances can be stored over time within sediment matrices and may subsequently be released into the aquatic environment, posing significant risks to the ecosystem integrity and biodiversity [1]. Among these contaminants, particular attention has recently been given to the emerging contaminants (ECs), a wide group of chemicals that are not subjected to regulatory control. This category includes some lipophilic substances that are the focus of the present investigation [2,3]. Traditional approaches for the extraction of contaminants from sediments and soil, such as Soxhlet extraction, vortex-assisted extraction, and ultrasonic baths, have been long employed in environmental monitoring. These methods usually require the use of large volumes of organic solvents, extended extraction times, and often necessitate additional clean-up steps, such as solid-phase extraction [1]. Furthermore, they offer limited flexibility in the adjustment of critical operational parameters, including solvent consumption. Consequently, there is growing interest in exploring alternative extraction strategies that are both effective and resource efficient. In this context, devices originally designed for everyday use can be repurposed for analytical applications. A notable example is the domestic coffee maker, the Moka pot, which enables solid-liquid-vapor extraction under elevated temperatures and moderately high pressures [4]. However, conventional Moka pots afford limited control over extraction parameters. To overcome these limitations, the present study explores the use of a Moka-like coffee machine, the Kamira, which enables more precise manipulation of the extraction variables and significantly shorter extraction times (approximately 30-40 seconds) [5]. This device also allows for adjustable solvent volumes, further enhancing its applicability in the analytical workflow. This study presents a comparative evaluation of three extraction techniques: traditional ultrasonic bath extraction, standard Moka-pot extraction, and Kamira extraction. Antarctic sediment samples, sourced from the Banca Campioni Ambientali Antartici (BCAA) at the University of Genoa, were artificially spiked with known amounts of selected ECs. The samples were then subjected to the three pre-treatment protocols. For the ultrasonic bath, 40 mL of acetonitrile-water (90:10, v/v) mixture was employed during the 2 minutes sonication. For the Moka and Kamira methods, 40 mL of the same solvent mixture were used to perform extraction directly from the coffee-holder unit, following procedures adapted from Baglietto et al. (2024) [4]. Extracts were then diluted to 50 mL, 1 mL was evaporated to dryness, and reconstituted using 100 µL of methanol-water (50:50, v/v) prior to analysis using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The results obtained indicate that the Kamira-based approach exhibits superior recovery rates and similar matrix effects compared to the ultrasonic bath and traditional Moka-pot methods. These findings highlight the potential of repurposed domestic devices as cost-effective and efficient alternatives for contaminant extraction in environmental analysis. Ongoing work is focused on the optimisation of key operational parameters through the application of experimental design methodologies. To our knowledge, this is the first study to systematically compare these three extraction strategies for the determination of ECs in Antarctic marine sediments. The proposed approach offers the perspective of a simple, low-cost, and effective tool for the monitoring of ECs in the environment, thereby contributing to a more comprehensive understanding of their distribution and ecological impact in polar regions. References: 1. Kuznetsova O. V., Timerbaev A.R., Analytica Chimica Acta, 2022, 1209. 2. Khan S. et al., Environmental Research, 2022, 207, 112609. 3. Lowther N., University Canterbury Thesis Archive, 2014, 1-16. 4. Baglietto M. et al., Advances in Sample Preparation, 2024, 10:100110. 5. Santoro N., Kamira Espresso Cremoso. https://www.espressokamira.net/