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EVAPORATIVE LIGHT SCATTERING DETECTOR


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CHROMACHEM

The Chromachem is the most flexible evaporative light scattering detector  integrating high level of sensivity  with lower evaporation temperature for both nebulizer and evaporation chambers.

The detector works as a stand alone unit or fully controlled by external devices through its RS232.

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Key advantages :

pastilleUniversal detection of non-volatile compound,

pastilleIdeal for lipids, carbohydrates, polymers, pharmaceuticals and compounds with weak chromophores,

pastilleCompatible with HPLC  gradient,

pastilleMore stable and sensitive than RI,

pastilleLow temperature operation even with water at high flow rate,

pastilleResponse factors less variable than RI, UV and MS.

CHROMACHEM technonology :

pastilleLight Scattering Detection has a technic which can detect any sample less volatile than the mobile phase used for the chromatographic separation.

Sensitivity is at least 20 times higher than RI detector and comparable, on the average, with UV detection.
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There are 3 steps in the detection process :

STEP 1
NEBULIZATION
Just after enter the detector the column effluent is mixed with inert gas, as nitrogen, and then transformed into small droplets to be evaporated more easily.This step determines the level of sensitivity and reproducibility of the detection.A control of the temperature (heating) increase those parameters.

 

 


STEP 2
EVAPORATION
The effluent droplets pass through a heated tubing where the the eluent is evaporated, only solute particles remain.To preserve uniformity of particle sizing and thermosensitive’s samples, CHROMACHEM uses a  special heating drift tube designed to operate at the lowest  evaporation temperature as possible.

 Schema


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STEP 3
MEASUREMENT OF THE SCATTERED LIGHT
The sample particles pass through a flow cell illuminated by a light source. A photomultiplier tube, placed at 120° from the light source, quantifies the light scattered by the sample particles and generates an electrical signal.The presence of chromophores is not necessary for detection.

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