The present invention relates to the field of laboratory-scale sample preparation, which describes a methodology for the specific isolation of tetraprotic naphthenic acids, called ARN acids, from residual naphthenate deposits from petroleum production.
The method consists of cleaning the naphthenate deposit, converting the naphthenate salts to naphthenic acids and isolating the ARN acids from the other organic acids, using a silica-based sorbent material with aminopropyl functional groups, previously selected for an efficient elution of different functional groups and polarities.