Waters 717plus - 4.5 Ensuring Reproducibility

Operating the Autosampler 86
4
4.5 Ensuring Reproducibility
This section covers:
• Overview of Reproducibility
• Purging the Autosampler
• Performing a Compression Check
4.5.1 Overview of Reproducibility
Reproducibility depends on:
• Purity of the mobile phase in the autosampler
• Compressibility of the mobile phase due to dissolved gas
• Integrity of the autoinjector sample loop
Ensuring Reproducibility
1. Run a purge and a compression check:
• To remove mobile phase that has been sitting in the system during a shutdown.
• To check the system on a daily basis for air or solvent leaks.
• To remove the previous mobile phase when changing to a new mobile phase.
• To establish the compressibility for a new mobile phase.
2. Run a purge and a compression check (see Section 4.5.3,
Performing a
Compression Check) on the degassed mobile phase.
3. If the mobile phase fails the compression check, degas the solvent (see Appendix C,
Reproducibility and Solvent Degassing).
4. If the degassed mobile phase again fails the compression check, run a leak test
(see Section 6.4.2,
Valve Leak Test) to verify the integrity of the sample loop.