This method is for determining the isomer distribution in C18 through C20 mono-substituted linear alkylbenzenes. 6-Phenyltridecane and 7-phenyltridecane isomers are not resolved from each other and are determined as a composite. The lower limit of detection for a single component is 0.1 mass-%.

Components other than linear alkylbenzenes are not determined by this method.