B.3.4 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.
Notice:
Using 100% water can cause microbial growth. Waters recommends changing
100% water solutions daily. Adding a small amount of an organic solvent (~10%)
prevents microbial growth.
B.4 Buffered solvents
Adjust the pH of aqueous buffers. Filter them, to remove insoluble material, and then blend them
with appropriate organic modifiers. After you use a buffer, flush it from the pump by wet priming
using at least five system volumes of HPLC-grade distilled or deionized water. When using a
buffer, choose good quality reagents, filtering them through a 0.2-μm membrane filter.
For shutdowns of more than a day's duration, flush the pump with a 20% methanol/water solution,
to prevent microbial growth.
Notice:
Some buffers can be incompatible with mass spectrometers. Consult the
documentation that accompanies your instrument for compatible buffers.
Recommendation:
To discourage microbial growth, replace 100% mobile aqueous phase
daily.
See also:
For information on preventing contamination, refer to
Controlling Contamination in
UltraPerformance LC/MS and HPLC/MS Systems
(part number 715001307) on the Waters Web
B.5 Other solvents
You can use the following solvents. Note, however, that these solvents can shorten instrument
life. If you routinely use the solvents on this list, Waters recommends you install the Hexane/THF
Compatibility Kit.
• Tetrahydrofuran (THF)
• Hexane
• Acetone
• Ethyl acetate
Note:
1 - 4% aqueous solutions of Hexafluoroisopropanol (HFIP) for oligonucleotide
applications.
Note:
HFIP should never be used in wash solvents.
Note:
For additional information, see
August 8, 2016, 715005049 Rev. C
Page 88
