How should I store the Spherisorb NH2 column when used with acetonitrile and water mobile phases? - WKB113003

ENVIRONMENT

• Spherisorb NH2 column
• Storage conditions

ANSWER

Flush with water, and then store in 70:30 ACN/H₂O for reverse phase if the column will be used within four days. For longer storage, use 100% acetonitrile.

ADDITIONAL INFORMATION

The NH2 chemistry lifetime is compromised in the presence of water. The amine ligand creates a basic environment inside the pores in the presence of water. These conditions hydrolyze the ligand from the silica particle as some silica is dissolved in the basic environment. The water also acts like a weak acid over time and further hydrolyzes the bonds that hold the amino ligand to the silica particle.

For additional information, see Section 24, page 31, "Column Storage", in the HPLC Troubleshooting Guide.