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ESI Calibration Solution: Caffeine, MRFA, Ultramark 1621
Thermo Electron Corporation
LTQ XL Getting Started
143
ESI Calibration
Solution: Caffeine,
MRFA, Ultramark 1621
Prepare 10 mL of ESI calibration solution
1. Pipet 200
μ
L of the stock solution of caffeine into a clean, dry 10 mL
volumetric flask.
2. Pipet 100
μ
L of the stock solution of MRFA into the flask.
3. Pipet 100
μ
L of the stock solution of Ultramark 1621 into the flask.
4. Pipet 100
μ
L of glacial acetic acid into the flask.
5. Pipet 5mL of acetonitrile into the flask.
6. Bring the volume of the solution up to the 10 mL-mark on the flask
with 50:50 methanol:water.
7. Mix the calibration solution thoroughly.
8. Transfer the solution to a clean, dry vial.
9. Label the vial
ESI Calibration Solution
and store it in a refrigerator until
it is needed.
Note
Use only glass pipets or stainless steel syringes when measuring
glacial acetic acid. Using plastic pipet tips causes contamination of
acid stock solutions that can introduce contaminants in the
calibration solution.