7
Optimizing the MS Detector with Your Analyte in APCI/MS Mode
Cleaning the MS Detector after Tuning in APCI Mode
Thermo Electron Corporation
LTQ XL Getting Started
129
5. Flush the sample transfer line, sample tube, and APCI probe thoroughly
with a solution of 5% formic acid in water (or with another appropriate
solvent), as follows:
a. Fill a clean, 250
μ
L Unimetrics syringe with an appropriate solvent.
b. While holding the plunger of the syringe in place, carefully insert
the needle of the syringe into the free end of the Teflon tube.
c. Flush the sample transfer line, sample tube, and APCI probe with
the solution by slowly depressing the syringe plunger. Visually check
that the solution is exiting the tip of the APCI probe on the inside of
the probe assembly. Use a lint-free tissue to gently remove the excess
solution as it exits the probe.
d. Remove the needle of the syringe from the Teflon tube.
6. Repeat step 5 with a solution of 50:50 methanol:water.
7. Reinstall the Ion Max ion source housing as described in
If you plan to run analytical samples in APCI mode, go to
“Acquiring APCI Sample Data Using the Tune Plus Window”
.
Note
The solvent that you use to flush the sample transfer line,
sample tube, and APCI probe assembly depends on the solvent
system you use to dissolve your samples. For example, if you are
using a buffered solution of a high concentration, an acidic solution
is appropriate.
