ObjectiveAssessing the uncertainty of ion chromatography in determining the content of perchlorate in drinking water to improve the accuracy and scientificity of detection result.MethodsBased on the evaluation principles and method of uncertainty measurement, this paper analyzed and discussed various factors that affected measurement, including standard substances, standard curve fitting, standard solution preparation process, instrument itself, sample repeatability measurement, sample stability, etc. Simultaneously, this paper compared and evaluated the repeatability measurements of standard solutions and samples at different times. And used WPS Office 2023 software for data organization and statistical analysis, analyzed and calculated the mean values, test standard deviation, and uncertainty values. The uncertainty components were statistically described using the composition ratio.ResultsWhen both the standard solution and the sample were measured once, a large degree of uncertainty was introduced. The number of measurements gradually increased, and the introduced uncertainty values gradually decreased. By parallel measuring the standard point 3 times and the sample 6 times, the determination result of perchlorate in the sample was 9.68 μg/L, and an extended uncertainty was 0.93 μg/L (the inclusion factor k was 2).ConclusionThe main sources of uncertainty in this method are calibration curve fitting (39.34%) and standard solution preparation process (19.36%), followed by standard substances (15.21%) and sample repeatability measurements (10.34%). Suggestions and strategies for reducing uncertainty have been proposed.