Noisy baseline on RI detector 2414 - WKB267529

SYMPTOMS

• Noisy baseline
• Can affect area reproducibility due to baseline pickup
• Noise fails specification and SQT noise and drift test

ENVIRONMENT

• 2410 Differential Refractometer
• 2414 Refractive Index Detector
• ACQUITY UPLC RI Detector
• ACQUITY UPLC H-Class
• ACQUITY UPLC H-Class Quaternary Solvent Manager (QSM)
• ACQUITY Arc

CAUSE

Solvent not homogeneous

Lines other than isocratic line have different solvents that slowly bleed into the flow, affecting RI signal (more of an issue on QSM and QSM-R).

Seal wash solvent also mixing with flow

FIX or WORKAROUND

Place all solvent lines into the same solvent bottle and prime thoroughly, including seal wash.

ADDITIONAL INFORMATION

Seal wash solvent affecting baseline in a cyclic way