Function and setup of the PlasmaQuant MS
PlasmaQuant MS product family
22
3.2.1
Sample introduction system
The sample introduction system is freely accessible in the sampling compartment.
The PlasmaQuant MS uses a four-channel variable-speed peristaltic pump to deliver
solution to the nebulizer and to drain waste from the spray chamber. One of these
channels can be used to pump an Internal Standard, so that it is added online to every
sample and standard.
A nebulizer is used to convert a liquid sample into a fine aerosol, which is introduced
into the spray chamber, where larger drops are eliminated. A Micromist concentric
glass nebulizer is supplied as standard with the PlasmaQuant MS. The nebulizer is
suitable for the routine analysis of most aqueous and organic samples. It produces a
free aspiration rate of 400 µL/min for a nebulizer gas flow of 1 L/min at a 2 bar
pressure.
The PlasmaQuant MS uses a Peltier-cooled spray chamber. The spray chamber is a
Scott type double pass glass design and is encased in a thermostated and insulated
holder assembly. Keeping the spray chamber cool increases temperature stability and
reduces water and solvent vapor. Reduced vapor limits the formation of oxides and
other interferences. The spray chamber and holder assembly are supported on a
mounting arm attached to the outer side wall of the PlasmaQuant MS that can be
swung outwards for installation and maintenance.
The PlasmaQuant MS uses a glass transfer tube to channel the aerosol from the spray
chamber into the injector of the torch.
The transfer tube for optional aerosol dilution has a gas port through which the sheath
gas is introduced. High-matrix samples, e.g. sea water, can then be diluted in the
sample introduction system. By adapting the nebulizer and sheath gas flows from the
software, the dilution can be variated to reduce matrix effects inline. Sample
preparation time is reduced to a minimum.
Fig. 3
Sample introduction system in the PlasmaQuant MS
1 Spray chamber
2 Thermostated holder assembly
3 Peristaltic pump
4 Nebulizer
5 Transfer tube (to the torch)
6 Glassware clamp
Pump, nebulizer and
spray chamber