Atakol, MelikeAkbıyık, HilalAtakol, ArdaYıldırım, VedatBakırdere, SezginAtakol, Orhan2025-04-182025-04-182025Atakol, M., Akbiyik, H., Atakol, A., Yildirim, V., Bakirdere, S., & Atakol, O. (2025). Development of a Solidification of Floating Organic Droplet-Based Liquid-Liquid Microextraction Method Utilizing a Schiff Base Ligand for the Determination of Nickel at Trace Levels in Saint John’s Wort Tea Infusions by Matrix Matching Calibration Assisted Slotted Quartz Tube-Flame Atomic Absorption Spectroscopy. Analytical Letters, 1-14.00032719http://dx.doi.org/10.1080/00032719.2025.2450520https://hdl.handle.net/20.500.12713/6661A sensitive and economical analytical method involving the solidification of floating organic drop microextraction technique with a dispersive solvent is utilized for extraction and enrichment of nickel in St. John’s wort tea infusions. Bis-N,N′-(salicylidene)-1,3-propanediamine was used as the complexing agent. The analyses were done with a slotted quartz tube-flame atomic absorption spectrometer (FAAS). The experimental parameters for the preconcentration procedure were optimized. The developed method provided a 26.5-fold enhanced detection power compared to determination by conventional FAAS. The limits of detection and quantification were 24 and 79 µg/kg, respectively, within a linear range of 50–500 µg/kg. The applicability of the method was tested on infusions of two samples of St. John’s wort tea. Matrix matching was adopted to eliminate/minimize the interferences on the signal. Spiked experiments in which high recovery values in the range of 89.3–121.4% were obtained indicate the accuracy and validity of the method. © 2025 Taylor & Francis Group, LLC.eninfo:eu-repo/semantics/closedAccessDispersive Liquid-Liquid Microextraction (DLLME)Environmental AnalysisFlame Atomic Absorption Spectrometry (FAAS)Green ChemistryHerbal Tea AnalysisArticleWOS:0013941719000012-s2.0-85214679920Q310.1080/00032719.2025.2450520Q2