Histamine is a basic compound that acts like neurotransmitter. Phenethylamine is a natural amine alkaloid psychoactive compound with stimulant effects. It forms by enzymatic decarboxylation of phenylalanine, and also acts as neurotransmitter. Both compounds are separated in one HPLC run on Primesep C and Primesep 200 columns by reversed-phase cation-exchange mechanism. Primesep C provides shorter retention time and histamine and phenethylamine can be separated within 5 minutes. Primesep C and Primesep 200 columns do not require ion-pairing reagent as it is attached to the surface of Primesep silica gel. Method can be used for analysis of these two compounds in plasma, blood and urine with UV, ELSD, CAD or LC/MS detection.