LC/MS Analysis of Omeprazole and Metabolites on Ascentis^® Express HILIC

column

Ascentis Express HILlC, 10 cm x 2.1 mm I.D., 2.7 μm particles (53939-U)

mobile phase

[A] 5 mM ammonium formate in water, pH 6.5; [B] 5 mM ammonium formate in acetonitrile, pH 6.5; (2:98, A:B)

flow rate

0.3 mL/min

column temp.

35 °C

detector

ESI(+), m/z 50-400

injection

0.1 μL

sample

1 mg/L each in mobile phase