LC/MS Analysis of L-Methionine Sulfoximine, Sulfone and Sulfoxide on Ascentis® Express HILIC
CONDITIONS
column
Ascentis Express HILIC, 10 cm x 3.0 mm I.D., 2.7 μm particles (53970-U)
mobile phase
[A] acetonitrile; [B] water with 0.1% formic acid, pH 3.5 with ammonium formate; (75:25, A:B)
flow rate
0.4 mL/min
pressure
1350 psi 93 bar
temp.
25 °C
detector
MS, ESI (+), TIC, m/z 150-300
injection
5 μL
sample
10 μg/mL in 90:10, methanol:water
Description
Analysis Note
L-methionine sulfoximine and L-buthionine sulfoximine are used in are used to prevent additional enzyme activity in Chinese hampster ovary (CHO) cell lines with supplemental Glutamine Synthase (GS). It is of interest to be able to monitor both purity of such molecules in order to control addition to cell media as well as for the assay of parent molecules during use. The analytes are highly polar and thus should be amenable to HILIC-LC-MS analysis. This first installment investigates the ability of Ascentis Express HILIC and Ascentis Express OH5 stationary phases for the separation of the methionine analog and related compounds as well as methionine and buthionine separations.
Legal Information
Ascentis is a registered trademark of Merck KGaA, Darmstadt, Germany