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Determination of inorganic corrosion inhibitors by ion chromatography
Kapiasová, Anna ; Kubíčková, Anna (advisor) ; Kozlík, Petr (referee)
Corrosion inhibitors are substances that prevent the internal surface of the cooling system from corrosion. Inorganic corrosion inhibitors contain inorganic anions that passivate the surface, thereby preventing the diffusion of oxygen into the system and protecting the surface from oxidation. This study is aimed at the development and validation of a method for the determination of inorganic corrosion inhibitors (specifically chlorides, nitrites, nitrates, hydrogen phosphates, sulfates and molybdates) by ion chromatography. The optimal separation of anions was achieved with a mobile phase consist of 3.3 mM sodium carbonate and 3.3 mM sodium bicarbonate (pH= 10.1) at 45 řC using the column Metrosep A Supp 7 (250 × 4.0 mm with particle size of 5 µm) (Metrohm, Switzerland). Under these conditions the analysis took 48 minutes. After validation, the method was used to determine corrosion inhibitors in real coolant samples. The peaks of the individual anions contained in the coolants were verified by spiking with standards of anions. The anion concentrations were determined from the areas of these peaks using the calibration curves. Key words ion chromatography, engine coolants, corrosion inhibitors, inorganic ions
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