Quantitative determination of carbon nanodots in processed foods using HPLC-SEC with fluorescence detection

This study presents a validated analytical method using high-performance liquid chromatography with size exclusion and fluorescence detection (HPLC-SEC-FLD) for the quantitative determination of fluorescent carbon nanodots (CNDs) in processed foods. Addressing the lack of reliable quantitative tools in this emerging field, the method demonstrates high sensitivity (LOD: 0.080 mg/L), excellent linearity (R 2 > 0.9993), and strong reproducibility (RSD < 2.2%) across diverse food matrices. The morphology, crystallinity, carbon structure, and surface functional groups of the glycine–sugar-derived CND standard (Gly-CSNDs) were characterized using TEM, XRD, Raman spectroscopy, and FTIR. A glycine-sugar-derived CNDs (Gly-CSND) standard was employed for calibration, enabling accurate quantification of CNDs in samples such as coffee, darkened fruits, and caramelized products. The method showed recovery rates of 98.5–101.2% in spiked samples and consistent results across laboratories, confirming its robustness. This platform offers a specific, precise, and scalable solution for assessing CNDs content in complex food systems. It supports future research into CNDs formation during food processing and their potential health implications, laying a foundation for regulatory monitoring and safety evaluation of nanomaterials in the food supply.