A Moka-like Extraction Method for Emerging Contaminants Analysis in Antarctic Marine Sediments

The analysis of marine sediments represents a fundamental approach for assessing anthropogenic pressures on aquatic environments. Marine sediments act as long-term sinks for a wide range of contaminants which can accumulate within sediment and subsequently be released into the water column1. In recent years, increasing attention has been directed toward emerging contaminants (ECs), a heterogeneous group of chemicals that are not yet regulated but are of growing environmental concern due to their persistence and potential ecological effects2,3. Traditionally, the extraction of contaminants from sediments relies on well-established techniques, including ultrasonic bath extraction. While effective, these methods are generally characterised by high solvent consumption, long extraction times and limited flexibility in the adjustment of key parameters1. Consequently, there is a growing interest in developing alternative extraction strategies that are efficient and resource conscious. In this context, devices originally designed for everyday use can be repurposed for analytical applications. Domestic coffee makers, such as the Moka pot, enable solid-liquid-vapor extraction under elevated temperatures and moderately high pressures4. However, conventional Moka pots offer limited control over extraction conditions. To address this limitation, the present study explores the application of a Moka-like coffee machine, the Kamira, which allows greater control over the extraction parameters5. A comparative evaluation of three extraction techniques (ultrasonic bath, Moka-pot and Kamira-based extraction) was performed using Antarctic marine sediment samples. The comparison demonstrated that the Kamira method achieved better results and was subjected to a further optimisation. Subsequently, the optimisation of the extraction parameters for the determination of ECs in marine sediments was achieved. A mixture process design was applied to optimise key process variables, including the solvent-to-sample ratio and acid concentration, as well as mixture variables such as solvent composition. A total of 28 experiments were carried out, revealing that mixture variables were generally more influential that process ones and that optimal extraction conditions were achieved using an ethanol-water solvent mixture. These results highlight the innovative potential of repurposed domestic devices as rapid, low-cost and effective tools for environmental analysis, offering a promising strategy for the monitoring of ECs in sensitive and remote ecosystems such as polar regions. References: 1. Kuznetsova, O. V. & Timerbaev, A. R. Marine sediment analysis – A review of advanced approaches and practices focused on contaminants. Anal. Chim. Acta 1209, (2022). 2. Khan, S., Naushad, M., Govarthanan, M., Iqbal, J. & Alfadul, S. M. Emerging contaminants of high concern for the environment: Current trends and future research. Environ. Res. 207, 112609 (2022). 3. Lowther, N. Emerging Contaminants in the Antarctic - A Review. Univ. Canterbury Thesis Arch. 1–16 (2014). 4. Baglietto, M., Benedetti, B., Di Carro, M. & Magi, E. Assessing the potentialities of an easy-to-use sample treatment strategy: Multivariate investigation on “Moka extraction” of typical ingredients from dietary supplements. Adv. Sample Prep. 10, 100110 (2024). 5. Santoro, N. Kamira Espresso Cremoso. https://www.espressokamira.net/.