PlasmaQuant PQ 9000 (Elite)
Fault removal
75
Check the pump tube for drainage; if necessary, select a larger cross-sec-
tion
The measured value is too high
Cause
Remedy
Calibration
Check the calibration solutions
The peak position has slightly shifted or
measurement takes place on a peak
shoulder
The spectral interference was overlooked
use another analysis line or
activate an interference correction
Contamination/carry-over
Find and remedy the cause for contamination/carry-over
Concentrations appear higher due to
volatile substances
Optimize sample preparation
The analyte is an alkali metal (or an
easily excitable atomic line)
Alkali effect
optimize the plasma temperature (nebulizer gas flow
and/or performance) and plasma observation
When using an internal standard
The standard dosage is wrong
The adjustment of the response to changes in the plasma temperature is
inadequate
1. Adjust the matrix
2. Find a better adjustment between the behavior of the analysis line and
the internal standard
The warm-up phase is not observed
Wait for the warm-up phase to complete before commencing calibration
The sample foams when shaken
There are surface-active substances in the measurement solutions
1. Optimize sample preparation
2. Also add the surface-active substances to the calibration solutions
Precision is poor
Cause
Remedy
The pump fast mode was activated up
to shortly before the measurement
Limit the fast mode to the time that is required to pass the measurement
solution up to the nebulizer
The prewash time is too short
Extend the prewash time
The nebulizer or injector is clogged
If necessary, check with Na solution (1 g/L) – if no plasma coloring (orange)
is observed:
Check the nebulizer nozzles for obstructions and clean them (see "Clean-
ing the nebulizer" p. 59)
If the sample nozzle is clogged
filter the solutions or use an in-line filter
If the argon nozzle is clogged
dilute the measurement solutions or use
an argon humidifier
The nebulizer gas flow is not optimal
Optimize the nebulizer gas flow
There are leaks in the argon supply
Seal the leaks
Drift
Cause
Remedy
Change in the temperature in the
spray chamber
A change of 1°C causes a drift of approx. 1%
Thermostatically control the spray chamber or ensure air conditioning in the
laboratory
The transparency in the UV vacuum is
not sufficient
Check whether the argon purging of the spectrometer is complete (activate
the purge gas flow long enough)