Objectives  A mathematical model was established to assess the uncertainty of sodium cyclamate content in beverages tested by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

Methods  Based on JJF1059.1-2012 about evaluation and expression of uncertainty inmeasurement, the sources of uncertainty for determination were analyzed and each component of uncertainty was evaluated.

Results  When the content of sodium cyclamate in beverages was 0.11 μg/kg, the confidence probability was 95%, comprising a factor of k=2, its extended relative uncertainty was 0.06 μg/kg.

Conclusion  Based on the analysis of uncertainty, it was found that the fitting residual error of standard curve was the main source of uncertainty; and then improved methods for quality control were put forward.