What are some possible causes for erratic and irregular baseline?

• Leaks may cause baseline noise; check for loose fittings, pump leaks, salt build-up, etc.
• Mobile phase may be contaminated, deteriorated, or prepared from low quality materials.
• Mobile phase solvents might not be miscible, causing the baseline noise.
• Air in the mobile phase, detector cell or pump may be causing the noise, so ensure mobile phase is degassed and flush system if necessary.
• Air bubbles in the detector should be purged; install a backpressure device post detector.
• Contaminants in detector cell may cause noise; clean with strong solvent or passivate.
• Check for UV lamp detector failure.
• Ensure mobile phase mixer is not malfunctioning if using gradient.