A method for analyzing 21 pesticide residues in 3 types of fruits was established using QuEChERs-UPLC-MS/MS. The samples were extracted using acetonitrile, purified through the utilization of multi-wall carbon nanotubes (MWCNTs) and PSA, detected by UPLC-MS/MS, and quantified using an external standard. The presented method was applied to the monitoring of pesticide residues in dominant fruits (peach, cherry and watermelon) from the diverse ecological planting zones in Jiangsu Province. Additionally, a dietary risk assessment was conducted for various age groups in China based on the monitoring results. The method demonstrated excellent linearity (1-200 mu g/L, R-2 = 0.9950-0.9999), with recoveries of 75.1%-109.6% at spiked levels of 5, 50, and 500 mu g/kg, and relative standard deviations of 3.28%-9.69%. The limits of quantitation of 21 pesticides in the three fruit substrates were 5 mu g/kg. Multiple Pesticide residues were detected in all three types of fruits from major producing areas. Insecticide imidacloprid was detected in 51.6% of peaches. In watermelons, the insecticide thiamethoxam was detected at 33.3%, and the fungicides azoxystrobin (36.1%) and difenoconazole (29.2%) were also frequently found. In cherries, the fungicides carbendazim and difenoconazole had detection rates of 38.9% and 47.2%, respectively. However, all detected levels were below the maximum residue limits (MRLs). The dietary risk assessment indicates that pesticide residues in three types of fruits pose no health risks to Chinese consumers of all ages, as exposure levels remain within safety thresholds. However, children and adolescents are identified as higher-risk groups, warranting enhanced monitoring and risk assessment for their dietary intake. The method offers simplicity, rapidity, high sensitivity, and accuracy, making it suitable for large-scale monitoring and risk evaluation.
