Abstract: Process for reducing the concentration of water-soluble carboxylic acids in a hydrocarbonaceous mixture which process comprises (i) taking a sample from the hydrocarbonaceous mixture and extracting the water-soluble carboxylic acids from the sample, (ii) subjecting the extracted water-soluble carboxylic acids to chromatography, (iii) calculating the concentration of water-soluble carboxylic acids in the hydrocarbon mixture based on the chromatography results, and (iv) reducing the concentration of water-soluble carboxylic acids in the hydrocarbonaceous mixture.