Precautions for Mobile Phase Selection and Use
XVII
CBM-20A/20Alite
Precautions for Mobile Phase Selection and
Use
CAUTION
• Do not use resin parts for the high-pressure tubing while pumping at high pressures.
Pumping at high pressure may cause resin tubing to be ruptured or disconnected, which could result in
mobile phase leaks. Please note the maximum withstand pressure of each part when resin parts are
used for the high-pressure tubing.
• If PEEK resin parts are used in the plumbing, do not use the following mobile phases.
These mobile phases weaken the PEEK resin, which could result in cracked plumbing
and mobile phase leaks.
Concentrated sulfuric acid, concentrated nitric acid, dichloroacetic acid, acetone,
tetrahydrofuran (THF), dichloromethane, chloroform, dimethyl sulfoxide (DMSO).
Note: Briefly using a weak solution of less than 0.5 % acetone in water (e.g. in order to check gradient
performance) will present no problems.
• Regardless of the material used in the plumbing, tubing connections are made of
resin. Therefore, do not use any mobile phases containing hexafluoroisopropanol
(HFIP), which could weaken or damage the resin and result in mobile phase leaks.
• Use only HPLC grade or comparable mobile phase, and filter it with a filter of 0.45 µm mesh or finer
before use to remove particulates and foreign matter.
• Halogen ions can corrode the stainless steel material (SUS316L) used in the plumbing, so if such
materials are used for the wetted parts of the equipment, avoid, as much as possible mobile phases
that contain halogen ions - such as KCl, NaCl and NH
4
Cl or mobile phases that generate halogen ions
in certain reactions. If such mobile phases must be used, clean all flow lines thoroughly with distilled
water immediately after analysis.
• When SPD or a similar UV detector is used for high-sensitivity analysis, be sure to use HPLC grade
mobile phases that have a low absorptivity of UV rays.
• Always degas the mobile phase, as air bubbles may tend to form during solvent mixing or during
temperature or pressure changes. Air bubbles may cause pump malfunctions and detector signal
noise.
• Understand the properties, including boiling points, firing point and viscosities, of the mobile phase.
"9.8 Mobile Phase Characteristics" P. 9-56.
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