LC/MS Analysis of Polypeptide Drugs on Ascentis^® Express RP-Amide

column

Ascentis Express RP-Amide, 10 cm x 2.1 mm I.D., 2.7 μm particles (53913-U)

mobile phase

[A] 10 mM ammonium acetate in water, pH 4.2; [B] 10 mM ammonium acetate in 90:10 (v/v) acetonitrile:water, pH 4.7

gradient

held at 20% B for 0.1 min; 20 to 80% B in 2.9 min; 80 to 20% B in 0.01 min; held at 20% B for 0.99 min

flow rate

0.3 mL/min

column temp.

35 °C

detector

TOF, ESI(+), m/z 100-2500

injection

3 μL

sample

1 μL/mL in 10mM ammonium formate, 80:20, acetonitrile:water