AB Sciex 4500 Series System User's Manual page 48

Basic Acquisition Methods
Figure 5-1 Ion optics path and parameters (Continued)
Item Parameter
1 DP (Declustering
Potential)
1 CUR (Curtain
Gas)
1 IS (IonSpray
Voltage)
1 GS1 (Gas 1)
4500 Series of Instruments
48 of 142
Parameter Use
Type
Compound The DP parameter controls the
voltage on the orifice, which
controls the ability to decluster ions
between the orifice and the
skimmer (or for systems with a
®
QJet
orifice and QJet Ion Guide). It is
used to minimize the solvent
clusters that may remain on the
sample ions after they enter the
vacuum chamber, and, if required,
to fragment ions. The higher the
voltage, the higher the energy
imparted to the ions. If the DP
parameter is too high, unwanted
fragmentation may occur.
Use the preset value and optimize
for the compound.
Source and The CUR parameter controls the
gas gas flow of the Curtain Gas™
interface. The Curtain Gas
interface is located between the
curtain plate and the orifice. It
assists in solvent evaporation and
prevents solvent droplets from
entering and contaminating the ion
optics. The gas flow should be
maintained as high as possible
without losing sensitivity.
Source and The IS parameter controls the
gas voltage applied to the electrode
that ionizes the sample in the ion
source. It depends on the polarity
and it affects the spray stability and
the sensitivity. This parameter can
be compound-dependent and
should be optimized for each
compound.
Source and The GS1 parameter controls the
gas nebulizer gas. The nebulizer gas
helps generate small droplets of
sample flow and affects spray
stability and sensitivity.
Ion Guide, between the
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System User Guide