title: Normal-phase high-performance liquid chromatography of porphyrin free acids on silica modified with tetraethylenepentamine.
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005029:Ethylenediamines; D005243:Feces / Q000032:analysis; D006801:Humans; D011164:Porphyrias / Q000175:diagnosis*; D011166:Porphyrins / Q000032:analysis* / Q000652:urine; D012822:Silicon Dioxide
chemical_list: D005029:Ethylenediamines; D011166:Porphyrins; D012822:Silicon Dioxide; C034269:tetraethylenepentamine