Biotage ELSD-1080, Operation Manual

Page: 52 / 59

Biotage ELSD-1080
Large baseline
offset Inefficient evaporation
High concentration of non-
volatile buffer or stabilizer
Contaminated diffuser
Optics heater failed
Increase the evaporator
temperature and/or gas flow
Use a lower concentration of
stabilizer, unstabilized
solvent or a more volatile
buffer (ammonium acetate
or ammonium formate)
Perform cleaning procedure
Refer to local distributor or
Biotage AB
Peak tailing Eluent particles lingering in
the optical chamber
Poor chromatography
Increase evap gas flow rate
Adjust flash separation
Spiky peak tops
but flat baseline Inconsistent nebulization due
to:
Incorrect gas being used
Poor regulation of inlet gases
Insufficient smoothing
Sample precipitation during
nebulization
Inconsistent pump flow rates
Nitrogen is the
recommended gas
– others can be used but
may not nebulize as
efficiently
Change gas to nitrogen or
evaluate different nitrogen
sources. If using bottled gas,
check that gas regulator is
functioning correctly and
giving consistent flow.
Alternatively, use a pulse
dampener
The broader the peaks, the
higher the smoothing value
is required. Increase
smoothing to 50 for Flash
separations
Reduce sample concentration
or inject same loading in
larger volume. Check sample
solubility in mobile phase
eluents
See remedy for pump
pulsation in the baseline
noise section
Detector fails to
zero Offset too high or output
unstable due to impurity in
mobile phase Stop pump flow and switch
off unit. Restart unit and A/Z
without liquid flowing
Refer to local distributor or
Biotage
52 Publication date: July 2010