Tulu, MetinBaskin, DilgesYilmaz, OzgeIslam, Muhammad NazrulKoyuncu, IkbalEren, Tarik2026-04-022026-04-0220260007-48611432-080010.1007/s00128-025-04171-12-s2.0-105032719453https://hdl.handle.net/123456789/30264https://doi.org/10.1007/s00128-025-04171-1This study reports a simple and efficient dispersive solid-phase extraction (DSPE) method using phosphonate ester-functionalized poly(amidoamine) (PAMAM) dendrimer-coated magnetic nanoparticles for the trace determination of Co(II) and Cr(III) in environmental samples by flame atomic absorption spectrometry (FAAS). The nanoparticles were synthesized and characterized by NMR, FT-IR, SEM, and TGA analyses. Under optimized conditions, detection limits were 0.8 & micro;g L(-)1 for Co and 1.9 & micro;g L(-)1 for Cr, with linear calibration ranges of 2.5-250 & micro;g L(-)1 and 5.0-500 & micro;g L(-)1, respectively. Compared with direct FAAS, the enhancement factor (EF) was 110 for Co and 204 for Cr. Recovery tests in spiked tap water and black tea infusions yielded recoveries of 79% to 114%, confirming the method's precision and applicability in real matrices. This approach provides a cost-effective and reliable alternative to advanced instrumental methods and demonstrates the potential of functionalized magnetic sorbents for trace metal monitoring in environmental and food analysis.eninfo:eu-repo/semantics/closedAccessPhosphonate EsterMagnetic NanoparticleDispersive Solid-Phase ExtractionFlame Atomic Absorption SpectrometryTrace MetalsPAMAM DendrimerArticle