Abstract: The study was aimed at evaluation of the measurement uncertainty in the determination of three plant growth regulator residues in bean sprouts by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/ MS). According to Evaluation and Expression of Uncertainty of Measurement (JJF 1059.1-2012), a mathematical model of uncertainty evaluation was constructed, and the sources of uncertainty were analyzed in depth, and each component was quantified and synthesized. The results showed that the main sources of uncertainty arose from the preparation of standard solution and curve fitting. Furthermore, the expanded uncertainty was 0.6, 2.3 and 2.3 μg/kg for paclobutrazol, indole-3-acetic acid and 3-indolebutyric acid contents of 5.9, 15.5 and 16.0 μg/kg in bean sprouts (k = 2), respectively.

Key words: ultra performance liquid chromatography-tandem mass spectrometry, paclobutrazol, indole-3-acetic acid, 3-indolebutyric acid, uncertainty, bean sprout