Objective To determine the concentration of cesium hydroxide in workplace air using solvent elution and flame atomic absorption spectrometry, assess the uncertainty of this method, determine the factors influencing uncertainty, and provide a reference for the detection of cesium hydroxide in the workplace air.

Methods The samples were collected using a microporous membrane. After elution with water, absorbance was measured using a flame atomic absorption spectrophotometer for quantification, with potassium chloride solution as an ionization buffer.

Results The uncertainties introduced during sampling and experimental analysis were 0.003 27 and 0.054 1, respectively. The synthetic uncertainty was 0.054 2. The concentration of cesium hydroxide was 0.621±0.067 mg/m³.

Conclusion The main source of uncertainty in the determination of cesium hydroxide in workplace air by flame atomic absorption spectrometry is the linear fitting of standard curve in the process of experimental analysis. Therefore, during the preparation and measurement of the standard series, it is crucial to maintain precision and adherence to standardized procedures.