NEBULIZE ELUENT AND SELECT SMALL DROPLETS TO MINIMIZE BACKGROUND NOISE

The eluent is transformed into a fine mist by the nebulizer. The SEDEX technology allows the selection of droplets as a function of size. Large droplets cause increased background noise because they are more difficult to evaporate. Click to learn more.

EVAPORATE AT LOW TEMPERATURE

Analyte molecules are obtained from the mist using a heated evaporation (drift) tube, at low temperature. SEDEX detectors are designed to evaporate high boiling mobile phases at very low temperatures. This unique feature minimizes the potential for thermal decomposition of the compound of interest, and makes the SEDEX method a more reliable way to detect everything in the sample.

DETECT LIGHT SCATTERING

The solute molecules from the mist, assisted by gas supported focusing (GSF), pass through an optical head designed to measure light scattering. Gas supported focusing (GSF) involves the addition of gas to focus the solute particles within the optical head for optimized sensitivity.

Why use LT-ELSD?

Provides an essentially universal measurement-
not dependent on a compound’s:
- Absorbance
- Electroactivity
- Fluoresence
- Radioactivity etc.
Provides mass detector capability
Minimizes volatilization of compounds through
low temperature evaporation
Allows gradient elution
Permits a wide choice of volatile buffers
Works with underivatized compounds
Surpasses RI sensitivity by orders of magnitude

What is Low Temperature Detection ?

The unique design of SEDEX LT-ELSD- Nebulization cell allows the selection of droplets as a function of size. Large droplets, which are more difficult to evaporate, are responsible for increased noise level. In the glass nebulization cell, the largest droplests are simply eliminated, so that the temperature can be lowered, without compromising the sensitivity (signal to noise ratio)

This diagram illustrates the selection of droplets as a function of size. The mist created by the nebulizer is composed of various sized droplets. The nebulization cell acts as a real size exclusion selector, so that the droplets of largest dimensions (in blue color) are eliminated. Only droplets below a certain size are allowed in the drift tube.

Selection of the droplets is a unique feature of SEDEX LT-ELSD and provides real low temperature evaporation, and the best sensitivity for all compounds, even semi-volatile ones.