Patent ID: 8487241

Claim:
A method for determining the amount of one or more analytes selected from the group consisting of epinephrine, norepinephrine, and dopamine, the method comprising: a. performing a protein precipitation for a urine sample provided at a pH below about 3 to generate a supernatant; b. subjecting the supernatant to electrospray ionization (ESI) under conditions suitable to produce one or more ions detectable by mass spectrometry; wherein: i. if one of the one or more analytes is epinephrine, said ionization comprises generating ions with a mass to charge ratio of 166.1±0.50; ii. if one of the one or more analytes is norepinephrine, said ionization comprises generating ions with a mass to charge ratio of 151.9±0.50; and iii. if one of said one or more analytes is dopamine, said ionization comprises generating ions with a mass to charge ratio of 136.9±0.50; and c. determining the amount of the one or more ions by mass spectrometry, whereby the amount of the one or more ions reflects the amount of said one or more analytes in the sample.