Landing microextraction sediment phase onto surface enhanced Raman scattering to enhance sensitivity and selectivity for chromium speciation in food and environmental samples. (1st September 2020) - Wang, Jingjing
Highlights: A model platform for chromium speciation. Ag nanoflower as SERS substrate for recording the [RG + .CrO3 Cl − ] SERS response. Reaction mechanism assignment of and optimization of extraction variables. Detailed comparison with literature and applications in real food and water samples. Standard method validation was performed using statistical tests. Abstract: The current study explores the first full mode liquid microextraction technique coupled with surface-enhanced Raman spectroscopy (SERS), and has been successfully applied for chromium speciation in food and environmental matrices. Herein, chromium as chlorochromate anion [CrO3 Cl] − and the cationic rhodamine 6G [RG] + dye has been extracted in organic phase as a complex ion associate [RG + .CrO3 Cl − .nS]org at pH ≤ 1.0. Afterwards, the extracted phase was deposited on the surface of the nano-flower shaped silver nanoparticles substrate and the SERS response was monitored against the reagent blank at 1505 cm −1 . Substrate characterizations, reaction mechanism assignment, stoichiometry, speciation, analytical applications, selectivity and validation were performed. The analytical procedure exhibits a detection limit of 0.03 µg L −1 under the optimized experimental conditions. The accuracy of the proposed strategy was validated by inductively coupled plasma optical emission spectrometry method using student's t- and F tests at 95% confidence.