• Methanol
• Methanol/water mixtures
• Methylene chloride
• Water
Recommendation:
Do not use buffers as needle wash.
B.9 Cleaning agents
Recommendation:
See the cleaning procedures in
Controlling Contamination in Ultra
Performance LC/MS and HPLC/MS Systems
(part number 715001307) on the Waters Web site.
Visit
www.waters.com
.
• Phosphoric acid (≤30%)
• Sodium hydroxide (≤1M)
• Formic acid (≤10%)
B.10 Solvents to avoid
Avoid these solvents:
• Solvents that contain halogens: fluorine, bromine, or iodine.
• Strong acids. (Use only in weak concentration, <5%, unless as cleaning agents. Avoid using
acids as mobile phases when their pH <1.0.)
• Peroxidizable compounds such as UV-grade ethers, non-stabilized THF, dioxane, and
diisopropylether. (If you must use peroxidizable compounds, be sure to filter them through dry
aluminium oxide to adsorb formed peroxides.)
• Solutions that contain strong concentrations of complexing agents like ethylene
diaminetetraacetic acid (EDTA).
B.11 System recommendations
Contact Waters for recommended system cleaning and flushing procedures.
Flush buffers from the system, with aqueous solvent, if you keep the system idle for extended
periods (longer than 24 hours). Use 10 to 20% organic solvent in water as a "storage" solvent.
Prime the sample manager-flow-through needle with wash solvent for a minimum of 30 sec and
purge solvent for a minimum of 10 cycles.
See also:
Controlling Contamination in UltraPerformance LC/MS and HPLC/MS Systems
(part
number 715001307) on the Waters Web site. Visit
www.waters.com
.
August 8, 2016, 715005049 Rev. C
Page 90
