PlasmaQuant PQ 9000 (Elite)
Function and setup of the PlasmaQuant PQ 9000
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Figure 1 Sampling compartment and plasma compartment
The PlasmaQuant PQ 9000 uses a free-running 40 MHz HF generator (High-Frequency
Generator). The HF generator transfers power ranging from 800 to 1700 W into the
plasma assisted by the high-performance coil. Fully automated matching of the power
output to the actual sampling loads in the plasma enables ultimate consistency of
plasma conditions. This means the plasma is very robust and is able to master even
challenging sample matrices such as organic solutions or salt loads. The HF generator is
located immediately behind the plasma compartment and is shielded separately because
of the high intensity of high frequencies.
The power for maintaining the plasma is transferred by means of an induction coil with
four windings in the torch in the plasma compartment. The induction coil is water-
cooled.
During the initial plasma ignition period, a high voltage spark is passed from the elec-
tronic ignition unit to the conducting spring located in the vicinity of the induction coil
through the high-frequency field in the torch.
A peristaltic pump conveys the measurement solution at the same rate to the nebulizer.
The rotational speed of the pump and the diameter of the pump tubing used determine
the amount of sample delivered. By using the pump, sample introduction into the nebu-
lizer and thus also the sensitivity of the measurement signal is nearly independent of
the viscosity of the measurement solution.
The aerosol of the measurement solution required for atomization/ionization in the
plasma is generated by a pneumatic concentric nebulizer. An argon flow is directed past
the sample nozzle of the nebulizer as nebulizer gas. The gas flow continuously tears the
surface of the liquid at the nozzle and produces small sample droplets. The sample aero-
sol that is formed is transported with the nebulizer gas through the spray chamber to
the plasma. On the way through the spray chamber, large droplets in the spray chamber
are separated by the centrifugal force and flow out via the waste outlet. A cyclone cham-
ber is used as the spray chamber.
HF generator
Pump, nebulizer and
spray chamber