Abstract:To establish a solid phase extraction (SPE)/high-resolution benchtop Q exactive mass spectrometry (HRMS) method for the analysis of morpholine in apples and citrus.Methods The samples were first extracted with 1% formic acid in acetonitrile-water (1∶1, V/V) and then cleaned up using SPE procedure. The chromatographic analysis was performed on a BEH HILIC column with 0.1% formic acid and 4 mmol/L ammonium formate in water/acetonitrile as the mobile phase with gradient elution. The internal standard calibration was used for quantification.Results The linearity was satisfying within 1-100 μg/L, and the coefficients of determination (r2) were above 0.999 for morpholine. The limit of detection (LOD) and the limit of quantitation (LOQ) were 5 and 10 μg/kg, respectively. The recoveries of the spiked apples and citrus samples at the levels of 10,0, and 100 μg/kg ranged from 81.3%-103.7%, with intra-day repeatability and inter-day reproducibility precision 2.7%-7.4% and 1.7%-8.1%, respectively.Conclusion The method was sensitive and accurate, and was suitable for the analysis of morpholine in apples and citrus.