This method is for determining low concentrations of gydrocarbons in lean UOP Udex process solvent. Benzene, toluene, C 8 aromatics composite, and C 9 + aromatics composite are determined. Light non-aromatics through C 9 paraffins, if present, are reported as a composite. Higher non-aromatics, i.e., greater than C 9, may interfere with the determination of benzene. The lower limit of quantitatin for each aromatic component is 3 mg/kg (mass-ppm),.