System Overview; Basic Principles Of Operation - Agilent Technologies InfinityLab 1290 Infinity II User Manual

Evaporative light scattering detectors

Table of Contents

Introduction to the Detector

System Overview

Nebulization

The eluent inlet is connected to the nebulizer via a short length of stainless steel

capillary tube. The incoming eluent stream passes through the heated nebulizer

and is mixed with the incoming nebulizer gas stream. The mixed gas and eluent

stream form an aerosol plume containing a uniform dispersion of droplets that

then passes as a continuous flow into the evaporator section. Any larger droplets

or the inefficiently nebulized droplets collect in the nebulizer chamber waste trap

and then drain off via the waste outlet into a collection bottle.

Evaporation

After nebulization, the atomized spray is propelled through the evaporation tube

assisted by the carrier gas. In the evaporator section, the solvent is removed

leaving a stream of dry particles of the analyte. A diffuser located in the

evaporator assists in the drying of the particles, acting as an efficient heat

exchanger, prevents ballistic particles reaching the scattering chamber and

randomizes the particle plume. The ELS Detector uses patented gas flow

technology in the evaporation zone to aid evaporation at low temperatures. By

adding a stream of dry nitrogen (evaporation gas) at the entrance of the

evaporator tube less volatile solvents (for example, water) are easily evaporated.

This evaporation gas is controlled by the user and facilitates subambient

operation.

Agilent InfinityLab ELSD User Manual

Table of Contents

Table of Contents