General Considerations - Agilent Technologies InfinityLab 1290 Infinity II User Manual

Evaporative light scattering detectors

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Using the Module

General Considerations

The ELS Detector should be thought of as a detector like any other designed for

liquid chromatography. The main distinguishing feature is the ability to evaporate

the solvent from the column eluent. Therefore, normal system setup precautions

should be remembered when starting to use the instrument. Any solvent that is

intended for use with the ELSD should be fully miscible with any previously used

in the liquid chromatograph. If there is any uncertainty, then a mutually miscible

solvent should be run through the system as an intermediate liquid. Flush the

sample loop also with miscible solvent where necessary. The intended eluent

should be thoroughly degassed, should not contain nonvolatile salts or material,

and should be fully compatible with the columns. All connections should be

made with zero dead volume fittings and tubing with an I.D. ≤0.254 mm

(≤0.010 in).

The ELSD requires nitrogen of purity >98 %, at an inlet pressure of 4.1 – 6.9 bar

(60 – 100 psi). If in-house nitrogen is not available, we recommend the use of a

nitrogen generator with a constant uninterrupted supply of high purity gas. Air

can be used with nonflammable solvent systems. The eluent of choice should be

fully volatile under the chosen detector parameters – any nonvolatilized eluent

will increase baseline noise and reduce sensitivity.

The ELS Detector is a destructive technique and must be placed last when used

in series with other detectors, or used with a flow splitter for semipreparative

applications, where partial sample collection is required.

Agilent InfinityLab ELSD User Manual

Table of Contents

Table of Contents