Grace Catalog 2008

analytical hplc
Evaporative Light Scattering Detectors
Leading the Way in ELSD Technology for More Than 20 Years
Alltech has more than 20 years of experience engineering and manufacturing Evaporative Light Scattering Detectors. Our global
network of dedicated application chemists and technical support professionals provides you with the comprehensive service and
support you need.
How Does It Work?
hplc instruments
ELSDs detect any compound less volatile than the mobile phase using a simple three-step process:
1. Nebulization
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2. Evaporation
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3. Detection
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Column effluent passes
through a needle and mixes
with nitrogen gas to form a
dispersion of droplets.
Droplets pass through a heated
“drift tube” where the mobile
phase evaporates, leaving a fine
mist of dried sample particles in
solvent vapor.
The sample particles pass
through a cell and scatter light
from a laser beam. The scattered
light is detected, generating
a signal.
Are There Any Limitations?
1. The mobile phase must be volatile.
2. The sample must be less volatile than the mobile phase.
ELSD Advantages Over Other LC Detectors
ELSD RI UV MS
CHART KEY
Sensitivity
Gradient Capability
Baseline Stability
Solvent Interference
Mass Balance
Excellent:
Good:
Poor:
more info
For more information about Evaporative Light Scattering
Detection, including applications, literature, and an informational
movie, visit www.elsd.com.
www.discoverysciences.com