Development and validation of a liquid chromatography‐mass spectrometry method for quantification of octadecylamine in the secondary circuit of a nuclear power plant in the presence of other amines

Abstract Octadecylamine (ODA) is the most widely used film‐forming amine in the nuclear industry. Its function is to minimize corrosion. In this work, we developed and validated a liquid chromatography‐mass spectrometry method that allows the quantification of ODA in the presence of other amines in the secondary system of nuclear power plants operating under all‐volatile treatment chemistry. Sample stabilities greater than 95% were achieved after 1 week of being taken in acetonitrile 1:1. The method showed a high selectivity allowing the measurement of ODA in the presence of other amines. The calibration curve was linear in the range of 0.0025–0.1025 mg/L. The limit of detection and limit of quantification (LOQ) were 1.8 and 2.2 µg/L, respectively for an injection volume of 3 µL. Lower LOQs can be achieved by increasing the injection volume, making the method applicable even in the first hours and days of treatment. The bias of the method was less than 10% and the relative standard deviation of reproducibility was less than 15%. The sample stabilization was robust and the uncertainty associated with the method was acceptable. The method was applied to a real sample taken after a few years of treatment and a concentration of 0.15 mg/L was measured.