This method is for determining total normal olefins (TNO), individual carbon number normal olefins, total normal paraffins (TNP), and individual normal paraffins in the UOP Pacol, UOP Define, and UOP Olex process feed and product streams. Samples can be in the C₉ to C₁₈ carbon number range, consisting of light ends (cracked by-products), normal paraffins, normal olefins, and associated non-normals compounds. Normal olefins include diolefins, if present. Small amounts of non-normals elute with the normal paraffins and normal olefins resulting in an approximate value for the total non-normals (TNN). A more accurate TNN value can be determined separately by UOP Method 411 (see Note 1). The lower limit of quantitation for any compound is 0.01 mass %. The lower limit of quantitation for any carbon number group is approximately 0.05 mass-%. .