Estudo de extratos de Armoracia rusticana e wasabi comercial como inibidores de corrosão do aço em meio HCl 1M usando MALDI-TOF

Abstract

Corrosion studies were performed using extracts of A. rusticana, commercial wasabi and their fractions through mass loss measurements, electrochemical impedance, and potentiodynamic polarization at concentrations of 100, 200, 400, 800, 1600, and 3200 mg L−1 in 1 mol L−1 HCl. The FT-IR, ESI-MS(±), MALDI-FT-ICR(±), and MALDI-TOF(±) techniques were used for the chemical characterization of the extracts and their fractions. The ethyl acetate fraction of crude ethanolic extract (WEP-EtOAc) showed the highest inhibition efficiency, above 96%, verified by mass loss measurement with and without temperature variation and electrochemical tests. SEM and XPS analyses were performed for surface analysis. MALDI-TOF was also used for the ethyl acetate fraction of WEP, where the laser was applied directly to the metal plate under study. Even after washing, the glucosinolate chemical group was identified as the major component on the metal surface. This study suggests that glucosinolates are the possible main corrosion-inhibiting phytochemicals in the extract.