A Comparative Determination of Chromotrope 2R Dye through Colorimetric and Fluorimetric Detection after Solid Phase Microextraction Using Spinel NiFe2O4

Aburub, Samer S.; Rahim, Nurul Yani; Mahmoud, Ashraf M.

doi:10.21608/ejchem.2023.239597.8691

A Comparative Determination of Chromotrope 2R Dye through Colorimetric and Fluorimetric Detection after Solid Phase Microextraction Using Spinel NiFe2O4

Document Type : Original Article

Authors

¹ School of Chemical Sciences, Universiti Sains Malaysia, 11800, Pulau Pinang, Malaysia

² Department of Pharmaceutical Chemistry, College of Pharmacy, Najran University, Najran 11001, Saudi Arabia.

10.21608/ejchem.2023.239597.8691

Abstract

In this study, a facile, convenient, and cost-effective vortex-assisted dispersive solid phase microextraction (VA-D-μ-SPE) was proposed to pre-concentrate chromotrope 2R dye (C2R) from watery media. Nickel ferrite nanoparticles (NiFe2O4 NPs) were used as an efficient sorbent for C2R, while colorimetric and fluorimetric methods were used to quantify C2R. The colorimetric method is based on measuring the native color of C2R at λmax 510 nm, while fluorescence sensing is based on quenching the fluorescence emission of red-emissive cationic carbon dots (rcCDs) at λem 680 nm via the electrostatic interaction and inner-filter effect (IFE). Factors affecting VA-D-μ-SPE and the determination were carefully optimized. Characterization of NiFe2O4 NPs and rcCDs was confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX), fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), UV/Vis spectroscopy, and fluorescence spectroscopy. The as-fabricated rcCDs exhibited a fluorescence quantum yield of 24.4%. It was found that the absorption intensities were increased linearly with increasing C2R concentration in the range of 10–60 µM with a detection limit (S/N = 3) of 3.1 µM, while the fluorescence intensities were decreased linearly in the range of 5–50 µM with a detection limit (S/N = 3) of 1.6 µM. The adsorption isotherm was best fitted to the Freundlich model with an R2 value of 0.9958 and a maximum adsorption capacity (qm) value of 151.5 mg.g-1. Adsorption kinetics was described by a pseudo-second-order model with R2 of 0.9962. Importantly, the VA-D-μ-SPE was successfully applied to determine C2R in water and tap water samples with acceptable percentage recoveries in the range of 92.6–102.4% and RSD % not more than 3.5%, suggesting the reliability of the proposed methods.

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