Page 28 of 34
SUPER SESI, by FIT
User manual, Revision 2.0
Stopping the electrospray
Reduce the pressure of the electrospray to zero. For this, open the valve 1 and reduce the
pressure down with the pressure regulator, or just opening the valve 2.
To stop the electrospray, set the voltage to zero. This voltage is controlled by the software of
the mass spectrometer (ionization voltage). Refer to the user manual of your mass
spectrometer.
To fully stop the electrospray, you can further set the MS to stand-by mode. Refer to the user
manual of your mass spectrometer for this. Once the mass spectrometer is set to the stand-by
mode, close the valve 1 (down) and open the valve 2 (up) to fully depressurize the electrospray
vial holder.
If you plan to stop the SUPER SESI for a long period of time, it is advisable to pull out the liquid
from the silica capillary. For this, close the valve 1 (down position), open the valve 2 (up
position), create a negative pressure with the syringe, close the valve 2 (down position), and
wait for the silica capillary to be emptied. When the silica capillary is emptied, the gas that comes
into the electrospray liquid vial through the silica capillary forms visible bubbles in the liquid.
High temperature cleaning cycle
INTERESTING NOTE
In normal operation, the temperature of the ionization chamber is limited
by the boiling point of the electrospray liquid. As a result, low volatility species tend to
build up in this region, thus increasing background signals. In order to remove this
contamination, it is advisable to rise the temperature from time to time so as to
evaporate these contaminants and to sweep them away.
If the spray is on, set the electrospray to zero. See section ‘Stopping the electrospray
´ for more
details.
Pass a continuous stream of gas through the capillary. For this, lift the back end of the silica
capillary within the electrospray vial holder so that it is not immersed in the liquid. After this,
open the valve 2 (up position) and pressurize the electrospray vial holder with the syringe.
At the MS control software, adjust the AUX GAS to ensure that a fraction of gas is counter-
flowing through the sample line, rise the SHEATH GAS, open the valve 1 (up) and close the valve
2 (down) to ensure a continuous supply of gas to the silica capillary. An overpressure of 500mBar
is enough to maintain a stable flow of gas.
Set the temperatures of the ionization chamber and the sample line to the maximum allowed
by their controllers (130ºC and 180ºC respectively) and let vapors be released for at least 30
minutes.
TIPS & TRICKS
A deep high temperature cleaning cycle can take up to one night.
Once the cleaning cycle is completed, set the normal operation temperature and wait for about
30 to 60 minutes for the new temperatures to stabilize. In order to return to the original
configuration, slide the back end of the silica capillary through the Upchurch fitting 2 and dip it
in the liquid.
Removing the SUPER SESI from the MS
If the spray is on, set the electrospray voltage to zero.
See section ‘Stopping the electrospray´
for more details. If the MS is acquiring, set it to stand-by mode. Refer to the user manual of your
mass spectrometer for this.
