A highly sensitive LC-MS/MS method for the determination and quantification of a recently identified -nitrosamine impurity in the sitagliptin phosphate monohydrate active pharmaceutical ingredient.

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was used for the quantification of 7-nitroso-3-(trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-]pyrazine (NTTP) in the sitagliptin phosphate monohydrate active pharmaceutical ingredient. Chromatographic separation was achieved using an Agilent-ZORBAX SB-C18 column, with 0.01 mol L ammonium formate in water as mobile phase A and acetonitrile as mobile phase B in gradient elution mode at a 0.