A process of removing at least one metal contaminant, such as copper, from a fluid hydrocarbon, for example, crude oil or a liquid hydrocarbon fuel, such as an aviation fuel. The process involves contacting the metal-contaminated fluid hydrocarbon with a sorbent selected from graphene oxide or a functionalized graphene oxide, particularly, a graphene oxide treated with a polycarboxylic acid, such as a saccharide polycarboxylic acid or a salt thereof, examples of which include alginic acid and Group IA and IIA salts thereof. The process removes greater than 99 percent of the metal contaminant without reducing concentrations of advantageous fuel additives, such as, antioxidants, icing inhibitors and corrosion inhibitors. Also described are a purified fluid hydrocarbon composition and a metal contaminant filter system.