D-2 Preparing samples for LC/MS system check with Empower software
Assembling required materials
You must assemble the following materials before starting to prepare your
sample:
• Solution kit containing 1 mg/mL sulfadimethoxine stock in methanol.
This solution kit is provided with your instrument.
• 1 L of solvent made up of 90:10 water/acetonitrile plus 0.1% formic acid
(v/v).
• Clean class A volumetric flasks: 100-mL (2), 10-mL.
• Clean class A pipettes (TD), 1-mL (3).
• PTFE-sealed screw-top amber sample bottles (glass or Nalgene™):
125-mL (2), 15-mL (2).
• Sample vial, 2-mL.
Preparing the sulfadimethoxine standard
The target mass of sulfadimethoxine on the HPLC column is 100 pg. Because
the supplied LC/MS System Check methods specify an injection volume of
10 µL, you must prepare a 10 pg/µL sulfadimethoxine solution.
To dilute the stock solutions to the final standard concentration:
1. Pour 1 mL of the stock solution into one of the 100-mL volumetric flasks.
2. Dilute to the 100 mL mark with solvent.
Result: The flask contains a 10 ng/µL sulfadimethoxine solution.
3. Into a second 100-mL volumetric flask, pour 1 mL of the solution created
in step 2.
4. Dilute to the 100 mL mark with solvent.
Result: The flask contains a 100 pg/µL sulfadimethoxine solution.
5. Into the 10-mL volumetric flask, pour 1 mL of the solution created in
step 4.
6. Dilute to the 10 mL mark with solvent.
Result: The flask contains the 10 pg/µL sulfadimethoxine standard
solution.