LC/MS Analysis of Methadone and Metabolites EDDP and EMDP 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 formate in water, pH 3.6; [B] 10 mM ammonium formate in acetonitrile, pH 3.6; (65:35, A:B)

flow rate

0.5 mL/min

column temp.

35 °C

detector

ESI(+), m/z 100-1000

injection

0.5 μL

sample

200 μg/L in 25:75, water: acetonitrile