Mobile Phase Guidelines For The Detector; General Guidelines - Thermo Scientific VH-D20 Operating Manual

6 • Operation
6.6

Mobile Phase Guidelines for the Detector

6.6.1

General Guidelines

Page 96
Observe the guidelines in the following sections for mobile phase use
with the charged aerosol detector:
CAUTION—Explosion Hazard or Damage to the Detector
When using tetrahydrofuran (THF), the use of air as supplied gas may
pose an explosion hazard. This can pose a safety and health risk and
damage the detector.
Always use nitrogen with tetrahydrofuran or other highly combustible
solvents.
NOTICE
Inappropriate or contaminated mobile phase can damage the detector.
The quality of the mobile phase significantly influences the performance
of the detector. Observe the following guidelines to avoid damage to the
detector.
• Use only volatile mobile phases. All constituents, i.e. solvents and
additives, of the mobile phase should be sufficiently volatile to allow
evaporation under the conditions used.
• Non-volatile solutes in the mobile phase, even at trace amounts,
produce a detector signal (background current, noise, drift).
Minimize their concentration.
TIP A careful consideration in the selection of the mobile phase
components will be helpful in minimizing the baseline noise and
optimizing the performance during analysis.
• Consider other possible sources of mobile phase and eluent
contamination.
Examples: Labware, pH electrodes, columns and system components
In many cases, it is preferable to use materials dedicated for use
only with volatile mobile phases.
• NP solvents: NP solvents are highly soluble in the gas and might
condensate in the gas exhaust tubing.
Charged Aerosol Detectors (VH-D20, VF-D20)
Operating Manual