Application of reverse flow injection analysis with liquid core waveguide for subnanomolar concentrations detection of copper in contrasted waters
Marine Chemistry, cilt.279, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 279
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.marchem.2026.104693
- Dergi Adı: Marine Chemistry
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Chemical Abstracts Core, Compendex, Geobase
- Anahtar Kelimeler: Copper, Liquid core waveguide, Nanomolar concentrations, Reverse flow analysis
- Orta Doğu Teknik Üniversitesi Adresli: Evet
Özet
Copper is a critical trace element in marine environments, acting as an essential limiting micronutrient in open ocean waters while posing toxicity risks at elevated concentrations in industrialized coastal zones. Accurate assessment of these contrasting roles necessitates rapid, selective, and precise analytical methods capable of in situ deployment. In this study, we adapted a colorimetric reverse Flow Injection Analysis (rFIA) method with Liquid Core Waveguide (LCW) detection for use on an automated chemical analyzer. By optimizing the protocol established by Wang et al. (2022) to address seawater-specific challenges, including temperature variations, salinity effects, and interferences from metals and sulfides, we achieved a subnanomolar detection limit (LOD = 0.03 nmol L−1 using a 1 m LCW). Method accuracy was validated through the analysis of certified reference materials NASS-7 and CASS-6. A critical operational constraint identified was the requirement to maintain a H₂S/Cu concentration ratio below 280 to prevent negative interference with the copper signal in sulfide-rich environments. The optimized method was successfully applied to diverse samples collected along a land-sea continuum, from the Aulne River and estuary, through Brest Bay to the Iroise Sea (France), as well as to discrete depth profiles from the Black Sea and the Sea of Marmara (Türkiye). These results validate a robust, reproducible, and highly sensitive approach for quantifying copper across riverine, estuarine, and marine systems with widely varying physicochemical conditions.