Objective In chemical analysis, the focus used to be on theprecision and accuracy of detection results. However, many testingactivities currently require establishing the credibility of theresults. Especially by measuring the credibility of the results to provetheir suitability, this generally includes the degree to which oneoutcome is expected to match other outcomes, which is also thesignificance of exploring uncertainty. Methods According to theCNAS-GL06 Guidelines for Evaluation of Uncertainty in Chemical Analysis,this article detected the content of phosphate ions in a certainindustrial wastewater and studied and analyzed the components thataffect measurement uncertainty during the experimental process. ResultsThrough calculation, it can be concluded that when the result ofphosphate ion is ${3.00}\mathrm{{mg}}/\mathrm{L}$ , theconfidence interval is ${2.86}-{3.14}\mathrm{{mg}}/\mathrm{L}\left({\mathrm{k}= 2}\right)$ . Conclusion The main factor affecting its measurement uncertainty is theuncertainty introduced by the calibration curve fitting. In order tomake the detection results more scientific and accurate, it is necessaryto pay attention to the maintenance and upkeep of the ion chromatographin daily work, minimize the background noise of the instrument, andimprove the sensitivity and accuracy of the instrument.

uncertainty  /  ion chromatography  /  phosphate