Patent ID: 8497079

Claim:
A method for determining the amount of glucagon in a sample by tandem mass spectrometry, said method comprising: a. subjecting the sample to ionization under conditions suitable to produce one or more ions detectable by mass spectrometry, wherein said ions comprise a glucagon precursor ion with a mass to charge ratio (m/z) of 871.1±0.50; b. fragmenting a glucagon precursor ion with a mass to charge ratio (m/z) of 871.1±0.50 to produce one or more fragment ions, wherein one or more of said fragment ions are selected from the group consisting of ions with m/z of 780.6±0.50, 841.8±0.50, 940.8±0.50, 1002.5±0.50, 1040.2±0.50, 1083.9±0.50, and 1122.2±0.50; c. determining the amount of one or more ions produced in steps a and b; and d. using the amount of the one or more ions determined in step c to determine the amount of glucagon in the sample.