Empower ToF technology with soft ionization of airborne molecules
SUPER SESI Sciex
What's the difference?
The inlet that communicates the atmospheric pressure side to the vacuum side of the mass spectrometer in Thermo and Sciex instruments is very different, and this is relevant to the performances of SESI ionization:
- Sciex features an orifice in a thin conical plate, which produces a supersonic jet that expands into a quadrupole (named Q-jet)
- Thermo utilizes a heated capillary, along which the gas is heated and expanded simultaneously
The expansion in Sciex is mainly adiabatic, while the expansion in Thermo more isotherm. For this reason, Sciex mass spectrometers incorporate a curtain plate that produces a counterflow gas, which prevents humidity from entering in the Q-jet region.
The counterflow gas can severely affect the performance of the SESI ionization if it's not properly handled. In particular, it can cause strong temperature gradients, which can have a negative impact on the stability of the eletcrospray, and memory effects of low volatility species.
change everything, so everything can stay the same
In order to accommodate the counterflow, SUPER SESI for SCIEX incorporates an extra heater floating at high voltage.
- This provides a uniform temperature
- The uniform temperature eases modelling and numerical optimization
- The internal geometry is optimized to maintain a laminar configuration despite the counterflow
The resulting configuration applies all principles and advantages of the SUPER SESI configuration*:
- Thermal optimization -
SUPER SESI for Sciex incorporates a redesigned curtain plate with a heat exchanger that floats at high voltage.
This provides a high uniform temperature:
- Improved electrospray stability
- Better control of ionization conditions
- Improved background levels
- Improved memory effects -
Reduced background levels
- Uniform and high temperature to eliminate cool spots and deposition of low volatility species
- Reduced exposed area
- Transfer line and ionizer made of silica coated SS-316, and teflon encapsulated seals
- New counterflow gas heater design impedes the entrance of sample gas even if unexpected high flows are introduced
- All parts are easily accessible for cleaning
- Reversed flow to reduce internal background contamination
- Continuous cleaning
- Steam-desorption cleaning
- Improved ionization efficiency -
The internal geometry is optimized to maintain a stable laminar configuration with the electrode-less configuration:
- Minimum dilution of neutral species
- Maximum the flow of ions passed to the MS
- Low exposed area