How do I make the Alliance 2695 compatible with normal phase solvent, such as THF? - WKB4337

ENVIRONMENT

• Alliance 2695

ANSWER

Review the Operator's Manual Appendix D for the recommended parts and solvents as referenced below:

1. Degasser chamber: Part number 700011709 PERFORMANCEPLUS VACDEGAS CHAMBER STENTED
   • The standard degasser chamber internal fittings can shrink and swell over time with normal phase and GPC solvents.
   • Normal phase solvent will cause the internally sleeved plastic tubing to fall off and the chambers to fill with solvent and fail.
2. Plunger seal recommendation: Review Appendix D  "GPC solvents and seal choices".
   • Part number WAT270938 for the SEAL, PLUNGER, PKG (2), 2690 (standard yellow seal, Fluoroloy G).
   • Part number 700001326 for the SEAL, CLEAR, 2 PACK, ALLIANCE (performance plus opaque seal, ultra high molecular weight polymer).
   • Note: Where other seals do not perform as expected in high organic composition, the use of black seals is another option:
     • Part number WAT271066 for the GFP Plunger Seal Kit (Optional Black).
3. Checkvalves.
   • Part number 700002399 PerformancePLUS CV Cartridge, Ceramic, 1/8-in.
   Seal wash recommendation: Review Appendix D "GPC solvents and seal choices".
   • The appropriate seal wash will extend the life of the plunger seals.
4. Solvent miscibility: Review Appendix D  "solvent miscibility chart".
   • If the difference between the miscibility numbers of the two solvents is 15 or less, they are soluble.
   • Prime all solvent lines, purge the injection pathway, and make injections of the intermediate solvent.
   • Using immiscible solvents can cause problems with baseline and pressure stability.

ADDITIONAL INFORMATION

• MTBE can also be used with the 2695.  
  • The clear seals are probably the best for this solvent.
  • Use 100% MeOH for the seal wash with MTBE mobile phase.