Evaluation of influencing factors and uncertainty of detection of trace uranium in drinking water using ultraviolet fluorescence
10.3760/cma.j.cn112271-20210709-00270
- VernacularTitle:紫外荧光法检测饮用水中铀的影响因素与不确定度评价
- Author:
Yuhan XIE
1
;
Liangliang YIN
;
Yuxin QIAN
;
Tingting XIA
;
Yanqin JI
Author Information
1. 中国疾病预防控制中心辐射防护与核安全医学所 辐射防护与核应急中国疾病预防控制中心重点实验室，北京 100088
- Keywords:
Uranium;
Ultraviolet Fluorescence;
Uncertainty;
Drinking water
- From:
Chinese Journal of Radiological Medicine and Protection
2022;42(4):291-296
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To achieve rapid and accurate detection of trace uranium in drinking water by analyzing the factors influencing the accuracy of uranium measurement in drinking water using ultraviolet fluorescence method and by evaluating the uncertainty in measurement.Methods:The influence of acidity, Fe 3+ and Mn 2+ contents on the analitical result were studied to optimize the measurement conditions. The accuracy of the measurement method was verified in 7 laboratories. By studying the errors introduced in the process of standard preparation, sample pretreatment and measurement, the sources of uncertainty were analyzed and the uncertainty was synthesized. Results:At pH 1-11 in aqueous solution, the linear regression coefficient of the standard curve was greater than 0.995, which was in line with the linear measurement range of the instrument. At pH 12 or so, the linear regression coefficient was 0.761, which could not meet the measurement requirements. At pH<3 or pH>10, the increase in fluorescence count was lower, which might increase the measurement error. At Fe 3+ concentration ≥15 mg/L, a large deviation occurred in measurement value that could affect seriously measurement result. At Mn 2+ concentration ≥ 1.6 mg/L, the sample produced white precipitation, which could affect the measurement accuracy. Three spiked water samples with different concentrations were determined in 8 laboratories. Each water sample was measured six times in parallel. The relative standard uncertainty of the result were 6.42×10 -2, 4.48×10 -2 and 5.26×10 -2 μg/L, and the expanded uncertainties were 0.03, 0.06 and 0.12 μg/L( k=2), respectively. Conclusions:The optimum conditions for the determination of uranium in water using this method pH were in samples 3-10, the concentration of Fe 3+ less than 15 mg/L, and the concentration of Mn 2+ less than or equal to 1.6 mg/L. The main sources of uncertainty in the measurement of uranium in water using ultraviolet fluorescence method arise from the repeated measurement error and the volume of added standard solution.
