Abstract: Using Morella rubra Lour. as the research subject, five fungicides with high detection rates (carbendazim, difenoconazole, pyraclostrobin, azoxystrobin, tebuconazole) were screened based on historical pesticide residues monitoring data from the Testing Center of Ningbo Academy of Agricultural Sciences. A systematic comparison was made on the technical performance of two detection methods: colloidal gold immunochromatographic rapid detection and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).The results showed that the detection limits of the immunochromatography method for the five fungicides were 0.20 mg/kg (carbendazim), 1.00 mg/kg (difenoconazole), 5.00 mg/kg (pyraclostrobin), 5.00 mg/kg (azoxystrobin), and 1.00 mg/kg (tebuconazole), respectively.The detection limits of the UPLC-MS/MS method for all five fungicides were 0.001 mg/kg.When the spiked levels of the five fungicides in Morella rubra Lour. were 0.010~1.000 mg/kg, the UPLC-MS/MS method demonstrated good accuracy and precision. The average recoveries of the five fungicides ranged from 74.8% to 107.5%, with relative standard deviations (RSD) between 1.1% and 9.0%.The immunochromatography method exhibited good precision. The false-negative rate for the five fungicides was 0, the false-positive rate was ≤5%, and the relative accuracy was ≥97.5%.Although the detection limits of the immunochromatography method were higher, they were all below the maximum residue limits. This method was fully applicable for qualitative screening of pesticide residues and met the timeliness and reliability requirements for on-site rapid detection.

Key words: Morella rubra Lour., fungicides, pesticide residues, detection methods, immunochromatography, comparative study