DSolvent Considerations
82 July 7, 2014, 715003736IVD Rev. C
Dirty solvents can cause baseline noise and drift, and they can clog solvent
reservoir filters, inlet filters, and capillary lines.
Solvent quality
Use MS-grade solvents for the best possible results. Filter solvents through a
0.2-µm membrane filter. Small particles can permanently block a system’s
capillary lines. Filtering solvents also improves check-valve performance.
Recommendation: Ensure that you choose solvents and membrane filters
that are compatible with each other and that you follow the manufacturers’
recommendations.
Solvent preparation
Proper solvent preparation, primarily filtration, can prevent many pumping
problems.
Store mobile phases in borosilicate glass reservoirs type 1, class A
2
or type
3.3
3
. Use brown-stained glassware to inhibit microbial growth. Use aluminum
foil or Waters caps to cover the reservoirs.
Water
Use water only from a high-quality water purification system. If the water
system does not deliver filtered water, filter the water through a 0.2-µm
membrane filter.
Recommendation: Use MS-quality (or better) water.
Using buffers
Adjust the pH of aqueous buffers. Filter them to remove insoluble material,
and then blend them with appropriate organic modifiers. After you finish
Caution: To prevent the proliferation of microbial colonies that clog
system filters and capillary lines, add a small amount (less than 10%) of
an organic solvent, such as acetonitrile or methanol, and completely
replace the mobile phase daily. Pure aqueous solvents must not remain
in a shut-down system because they serve as a substrate for microbial
growth.
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