Instruction manual

Precautions for Mobile Phase Selection and Use

RF-20A/20Axs

Precautions for Mobile Phase Selection and

Use

!CAUTION

• 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), fluorine organic solvents such as

hexafluoroisopropanol (HFIP)

Note: There is no problem with temporarily using a low-concentration aqueous solution with an acetone

concentration of 0.5 % or less, e.g. for the purpose of checking the performance of the gradient.

NOTE

• 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 avoid, as

much as possible, mobile phases that contain halogen ions - such as KCI, NaCI and NH

Cl - or mobile

phases that generate halogen ions in certain reactions. If such mobile phases must be used, clean all

flow lines thoroughly with 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 viscosities, of the mobile phase.

^ "9.5 Mobile Phase Characteristics" P.9-48