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

Carbon dots (CDs) have been widely used in the detection of pesticide residues in foods owning to their easy surface functionalization, adjustable characteristic, stable photoluminescence properties, and high water solubility. Because CDs have variety of functional groups that could achieve multiple retention mechanisms when it as functional ligands for silica gels-based stationary-phases. However, there have no CDs to optimize the retention of propamocarb (PM) in liquid chromatography based on the adsorption capacity of CDs. In this work, a new CDs (NM-CDs) was obtained by a simple hydrothermal method via using citric acid and glucose as two carbon sources. The analysis results of high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for 0.001-0.1 μg/mL PM that showed excellent retention from 0.9-2.4 min to 0.7-1.4 min, and a single chromatographic peak when added NM-CDs. At the same time, NM-CDs improved the signal-to-noise ratio and stabilized the mass spectrum for PM. Thus, the addition of NM-CDs has improved the efficiency of the chromatographic process, and the stability and sensitivity of detection concentration PM in the C18 chromatography column. Meanwhile, the excellent results were also revealed in the detection of PM with pesticide multiresidue and complex matrix, which has provided an effective implementation for CDs to detect pesticide residues in food at separation science. .