title: Is commercial "cerulein" always true cerulein?
mesh_terms: D000596:Amino Acids / Q000032:analysis; D002108:Ceruletide / Q000032:analysis; D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006863:Hydrogen-Ion Concentration
chemical_list: D000596:Amino Acids; D002108:Ceruletide