Determination of major and trace elements in glycol-based fluids by inductively coupled plasma atomic emission spectrometry

Abstract

The development of an analysis based on inductively coupled plasma atomic emission spectrometry (ICP-AES) is reported for the determination of 14 major and trace elements in coolant/antifreeze solutions to provide information on composition of new solutions and wear metals in used solutions. The evaluation of new coolant/antifreeze formulations for aluminum cooling systems has indicated that corrosion protection and stability are strongly dependent on the concentrations of the various components of the solution. The inhibitors include inorganic salts, such as silicates, borates, phosphates and molybdates, and these components are now determined by traditional analytical methods based on gravimetric and titrimetric techniques, spectrophotometry, atomic absorption spectrometry, and ion chromatography. The ICP-AES method may be used to replace these techniques with a simultaneous determination of four inhibitors as well as wear metals in used coolant/antifreeze solutions. The total time for analysis is reduced from several hours to approximately 15 min per sample. The relative standard deviation for the determination of the inhibitors is typically 2%. The detection limit for most of the wear metals is on the order of 0.1 mg l −1.