Development of a method for sampling and determination of corrosion inhibitors in modified atmospheres

• Published in: Measurement : journal of the International Measurement Confederation 2015-01, Vol.60, p.276-282
• Main Authors: da Silva, Letícia Caetano, Pereira, Elisabete Alves, Cardoso, Arnaldo Alves
• Format: Article
• Language: English
• Subjects: Amines; Capillary electrophoresis; Protective atmosphere; Suspended droplet; Volatile corrosion inhibitors (VCIs)
• ISSN: 0263-2241; 1873-412X
• DOI: 10.1016/j.measurement.2014.10.005

•We have determined some anti-corrosive amines.•Droplets were successfully used to collect volatile amines.•The amine amount quantified in the IVC product is not enough to saturate the atmosphere. A simple and rapid analytical method was developed to determine concentrations of amines used as volatile corrosion inhibitors (VCIs) in protective atmospheres. A microdroplet (16.9μL) of an absorbent solution (ethanol/water) was used to collect vapor phase VCIs. Simultaneous separation and determination of the amines was performed using capillary electrophoresis (CE), with indirect detection at a wavelength of 214nm. The technique was used to measure monoethanolamine (MEA), monocyclohexylamine (MCHA), and dicyclohexylamine (DCHA). It was possible to detect amine in a standard atmosphere after a short time (10min, including extraction and quantification), while best results were obtained for a total analysis time of 30min. The method was used to analyze the composition of commercial materials used as VCIs, and revealed that DCHA was the main compound present, with the quantity of inhibitor contained in the plastic support being considerably greater than the amount in the vapor phase.