Monitoring of fluoride in the public water supply using electrometric or colorimetric analyses

Abstract The surveillance of the concentration of fluoride in the public water supply aims to ensure the balance between the benefits (carie prevention) and risk (dental fluorosis) of water fluoridation programs. The aim of this study was to check the accuracy of two analytical methods for monitoring the concentration of fluoride in the public water supply of a Brazilian city. The STROBE checklist was used to aid the conduction of this study and report the results. It was an analytical, observational, and prospective study using the water supply of Uberlândia, MG, Brazil. We collected 126 water samples at 21 sites for six consecutive months and analyzed them using the fluoride ion selective electrode (F-ISE) method and colorimetry with SPADNS. The statistical analysis was performed descriptively and then the ANOVA and Student t-test for paired samples were applied. The results showed that the F-ISE method had a lower coefficient of variation (12.3%) than the SPADNS method (57.4%). There was no significant variation of the fluoride concentration in the water through the supply network evaluated either by F-ISE as SPADNS. We concluded that the electrometric method should be the first choice for use by laboratories that monitor fluoride concentration in the public supply water.摘要：公共供水氟浓度监测的核心目标是保障饮水氟化项目的收益（龋病预防）与风险（氟牙症）之间的平衡。本研究旨在验证两种用于巴西某城市公共供水氟浓度监测的分析方法的准确性。本研究采用STROBE检查表（STROBE checklist）辅助研究开展与结果报告，是一项在巴西米纳斯吉拉斯州乌贝兰迪亚市实施的分析性、观察性前瞻性研究。研究团队连续6个月在21个采样点采集了126份水样，分别采用氟离子选择性电极（fluoride ion selective electrode, F-ISE）法与SPADNS比色法开展检测。统计分析先进行描述性分析，随后应用配对样本方差分析（ANOVA）与Student t检验。结果显示，氟离子选择性电极法的变异系数（12.3%）低于SPADNS法（57.4%）；两种检测方法均未在所评估的供水网络中发现水中氟浓度存在显著变化。本研究结论认为，对于开展公共供水氟浓度监测的实验室而言，电分析法应作为首选检测方法。