Cone Wash System - Thermo Scientific Surveyor MSQ Plus Hardware Manual

Unsuitable Additives

Cone Wash System

Thermo Scientific
Unsuitable additives include:
• Surface-active agents
• Detergents
Surface-active agents and detergents can suppress the ionization of other compounds.
Detergents, by their very nature are concentrated at the surface of a liquid. This causes
problems with electrospray as the ionization relies on the evaporation of ions from the surface
of a droplet. The detergent therefore suppresses the evaporation of other ions. Use surfactants
only when they are being analyzed themselves, not as additives to HPLC mobile phases.
Historically, LC/MS has only been compatible with volatile buffer systems using modifiers
such as trifluoroacetic acid, formic acid and acetic acid. Phosphate buffers, although
extensively used in LC separations, were not suited to LC/MS due to the rapid blocking of the
ion sampling region caused by the deposition of non-volatile phosphate salts. The
self-cleaning API source (provided by the cone wash system) of the Surveyor MSQ Plus MS
detector allows routine LC/MS with chromatographic buffers such as phosphates or ion
pairing agents and samples in dirty matrices.
The cone wash system consists of a cone wash nozzle, internal tubing, and a cone wash pump.
Refer to your Surveyor MSQ Plus Getting Connected manual for instructions on connecting the
cone wash pump to the Surveyor MSQ Plus MS detector. The recommended flow rate for the
cone wash solvent is 200 μl/min and the recommended cone wash solvent is [50:50]
methanol / water (v/v).
Note It is necessary to use the cone wash only for dirty matrices or with non-volatile
buffers. Choose the cone wash solvent to give the most effective solubility for the expected
contaminants.
To optimize the position of the cone wash nozzle:
1. Turn the cone wash nozzle counterclockwise until the tip of the nozzle is just above the
top of the entrance cone.
2. Turn the cone wash pump on by turning its On/Off switch to On.
3. Adjust the nozzle so that the drops of solvent just touch the tip of the entrance cone as
they fall to the drain at the bottom of the Source chamber.
CAUTION Do not leave the cone wash running when the source heater is turned off
as this can lead to cone wash solvents condensing on the RF/dc prefilter.
A
Optimizing the LC Conditions
Cone Wash System
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