HPLC Analysis of Acetaminophen, Caffeine, Chlorpheniramine, Ibuprofen, Naproxen, Phenylephrine, and Pseudoephedrine on Ascentis^® Express C18

column

Ascentis Express C18, 5 cm x 2.1 mm I.D., 2.7 μm particles (53822-U)

mobile phase

[A] 5 mM ammonium phosphate monobasic, pH 2.0 with phosphoric acid: acetonitrile (98:2); [B] acetonitrile;

gradient

0 to 68% B in 3 min; held at 68% B for 2 min

flow rate

0.4 mL/min

column temp.

35 °C

detector

UV, 210 nm

injection

1 μL

sample

100 μg/mL in 95:5, water: methanol