Thermo Scientific thermoscientific Vanquish UHPLC System, Operating Manual

Page: 89 / 148

6 • Operation
UHPLC System
Operating Manual Page 89
6.5 Use of Solvents and Additives
Particles entering the chromatography system can block capillaries and
valves, increase wear, and damage the column or system. Especially with
aqueous solvents, algae and other microorganisms can grow and deposit
in the chromatography system and block the solvent line filters. Blocked
capillaries or filters can cause increased or unstable system pressure.
For optimum performance of the chromatography system, observe the
following guidelines:
• Be sure that the substances you are using are compatible with all
parts in the flow path.
• Use high-quality high-purity solvents (filtered) and additives as
required by the application, for example, UHPLC-grade or LC/MS-
grade. If a fluorescence detector is used in the system, consider
using fluorescence-grade solvents.
Filtered high-purity solvents are usually labeled accordingly by the
vendor.
• When preparing salt solutions or buffers and preparation is
complete, use membrane filtration (0.2 µm) to remove any
particulate matter and to reduce microbial growth.
• When using water, use high-quality water for example, UHPLC-grade
or LC/MS-grade (0.2 µm filtered). When you use water from water
purification systems, keep in mind that polymeric contamination
may occur if the purification system is not maintained properly.
• Before filling a solvent reservoir, always rinse the reservoir
thoroughly with a high-purity solvent.
• Use fresh solvents at regular intervals. Avoid adding up (refreshing)
solvents. With premixed solvents, be especially sure that they are
properly prepared and fresh.
• Before changing from a buffer or salt solution to organic solution,
flush the pump thoroughly with de-ionized water.
• When changing to a different type of solvent, make sure that the
new solvent is miscible with the previous solvent. If the solvents are
not miscible, flocculation may occur.
Mix immiscible solvents with an intermediate solvent to replace
them step by step. For example, use isopropanol.
• Always use the appropriate solvent line filters as recommended by
Thermo Fisher Scientific. Check the filter frits for permeability at
regular intervals and replace them as necessary.