• If the solution precipitates salt when coming into contact with the sample, then use a solution that is similar
in composition to the mobile phase and that does not contain salt.
• If the component to be analyzed tends to cause the sample to remain on the outside of the needle (for example,
if it is an acidic, basic, or ionic material), then use the following rinse solutions:
• Organic solvents, including methanol or acetonitrile, with an acid such as formic acid or acetic acid added.
• 0.1% trifluoroacetic acid (TFA) aqueous solution or organic solvent solution, or a mixture of the two.
Non-aqueous Normal Phases and GPC
Use the same solution for the rinse as for the mobile phase.
When the target compound is an acid, base, or ionic substance, and the rinse mode is required, use a 0.1% TFA
aqueous solution, an organic solvent solution, or a mixture of both.
Guidelines for Using High Concentrations of Volatile Acids
If the rinse solution contains high concentrations of volatile acids (formic acid or acetic acid at a concentration
exceeding 1% or TFA at a concentration exceeding 0.1%), then volatile components generated during lengthy
serial analyses might cause the metal parts inside of the module to rust, resulting in malfunctions. Follow these
guidelines when using high concentrations of volatile acids:
• Avoid using acid solutions with concentrations exceeding the following concentrations by diluting before use:
• Formic acid and acetic acid solution at a concentration exceeding 1%
• TFA solution at a concentration exceeding 0.1%
• After the analysis finishes, replace the rinse solution with a liquid that does not contain acid, such as HPLC-grade
water or methanol, and then remove the sample racks to ventilate the inside of the module.
• After the analysis finishes, keep the Z mount waiting in a position away from the rinsing port.
Rinse solution always accumulates at the rinsing port and its volatilized acid is at a high concentration, especially
around the rinse port. When the needle is inserted in the injection port, the Z mount is in the closest position
to the rinsing port, which might cause the motor of the Z mount to rust. To avoid rust, on the System Parameter
Setting screen, set
Z Home Mode
in the
Autosampler
tab to
Enabled
. This function keeps the Z mount
waiting in a position away from the rinsing port when the device shuts down, where the mount is least affected.
However, if a buffer solution is used as the mobile phase, be sure to set
Z Home Mode
to
Disabled
. Salt
might be precipitated at the tip of the needle and the upper side of the needle seal, which can cause clogging.
Guidelines for Using a Buffer Solution
When a buffer solution is used as the mobile phase, tubes might become clogged, depending on the buffer solution
used. Follow these guidelines:
• During autosampler injection, the rinse solution and the mobile phase are mixed in the tubing between the
high-pressure valve and the low-pressure valve. Verify that no salt is precipitated when the rinse solution and
the mobile phase are mixed.
Hardware User Guide
ExionLC
™
100 System
RUO-IDV-05-1839-C
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Operating Instructions
