Carbon dots derived from citric acid/glucose enhance the retention of propamocarb in reversed-phase chromatography

Abstract

Abstract Carbon dots (CDs) have been widely used in the detection of pesticide residues in foods owing to their easy surface functionalization, adjustable characteristics, stable photoluminescence properties, and high water solubility. CDs have a variety of functional groups that can offer multiple retention mechanisms when they are used as functional ligands in silica gel-based stationary phases. However, there are no CDs that optimize the retention of propamocarb (PM) in liquid chromatography based on the adsorption capacity of CDs. In this work, the CDs (NM-CDs) were obtained by a simple hydrothermal method using citric acid and glucose as two carbon sources. Analysis results obtained using high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) for 0.001–0.1 μg ml−1 PM showed excellent retention times from 0.9–2.4 min to 0.7–1.4 min and a single chromatographic peak when NM-CDs were added. At the same time, NM-CDs improved the signal-to-noise ratio and stabilized the mass spectrum of PM. Thus, the addition of NM-CDs improved the efficiency of the chromatographic process as well as the stability and sensitivity of the detection of the concentration of PM in the C18 chromatography column. Meanwhile, excellent results were also revealed for the CD-based detection of PM in pesticide multiresidues and complex matrices, demonstrating an effective approach for detecting pesticide residues in food within separation science.