1290 Infinity Quaternary Pump User Manual 89
Using the Module
4
Algae Growth in HPLC Systems
Algae Growth in HPLC Systems
The presence of algae in HPLC systems can cause a variety of problems that
may be incorrectly diagnosed as instrument or application problems. Algae
grow in aqueous media, preferably in a pH range of 4-8. Their growth is
accelerated by buffers, for example phosphate or acetate. Since algae grow
through photosynthesis, light will also stimulate their growth. Even in distilled
water small-sized algae grow after some time.
Instrumental Problems Associated With Algae
Algae deposit and grow everywhere within the HPLC system, causing the
followng problems:
• Blocked solvent filters, or deposits on inlet or outlet valves, resulting in
unstable flow, composition or gradient problems, or a complete failure of
the pump.
• Plugging of small-pore, high-pressure solvent filters, usually placed before
the injector, resulting in high system pressure.
• Blockage of PTFE frits, leading to increased system pressure.
• Plugging of column filters, giving high system pressure.
• Dirty flow cell windows of detectors, resulting in higher noise levels (since
the detector is the last module in the flow path, this problem is less
common).
How to Prevent and-or Reduce the Algae Problem
• Always use freshly prepared solvents, especially use demineralized water
which was filtered through 0.2 m filters.
• Never leave mobile phase in the instrument for several days without flow.
• Always discard old mobile phase.
• Use the amber solvent bottle ( Solvent bottle, amber, 1000 mL (9301-6526))
supplied with the instrument for your aqueous mobile phase.
• If possible add a few mg/L sodium azide or a few percent organic solvent to
the aqueous mobile phase.
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