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PLC with inteGrateD eLSD ConfiGuration
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PLC 2050/2250/2500 PurifiCation SyStemS
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Select the Optimum Temperature
there are two factors that should be taken into account when selecting the optimum
temperature for the detector:
●
increasing temperature will optimize the evaporation of the mobile phase.
●
Decreasing temperature will minimize the decomposition of thermally labile compounds
and the volatilization of semi-volatile compounds.
a very reasonable start is to set the temperature to 60°C if an aqueous mobile phase is
used and 40°C if an organic mobile phase is used (these temperatures are suggested for a
flow rate of 1 mL/min). at higher flow rates, more elevated temperatures may be required to
minimize the noise.
if the mobile phase used is not easily volatile, such as DmSo or Dmf, temperature should be
increased to allow correct evaporation process.
the temperature can be readily adjusted during the method optimization process.
if you suspect that the compound of interest is thermally labile or semi-volatile, a lower
temperature could be used to improve the sensitivity by reducing the thermal decomposition
or evaporation. for a given flow rate and solvent, there is, however, a point at which the
noise in the chromatogram is dramatically increased because not all of the mobile phase is
vaporized.
the minimum temperature that can be used is dependent on the flow rate and the nature of
the mobile phase.
Pretreat the Sample
if the sample contains any particulate matter, it should be filtered through a 0.2 or 0.45 µm
filter before injection.
Treat the Column
the chromatographic column typically contains microparticles which are used to separate the
compounds of interest. under certain conditions, the column packing will undergo chemical
and/or mechanical breakdown, this may lead to the introduction of particulate matter into the
detector, which may lead to an increase in the noise.
the breakdown of the column packing is dependent on a variety of factors including the
particle size, type of column packing, the manufacturer of the column and the nature of the
mobile phase (high ph may degrade silica based columns).
when you install a new column, we suggest to pump the mobile phase through it for few
minutes before connecting it to the detector. this will flush out the microparticles that
remained in the column after its manufacture.
