Film-forming amines (FFAs) are increasingly used in power plants and industrial steam systems as part of advanced water treatment strategies to prevent corrosion. FFAs offer significant benefits in terms of corrosion control and system longevity, but their presence in water and steam circuits can interfere with the accuracy of certain online analytical instruments. This Waltron Process paper explores the impact FFAs have on Sodium analyzers, which are critical for detecting Sodium contamination in high-purity water systems. The study investigates the effects of three different commercial FFA products on the performance of a standard Sodium analyzer.