TUV/PDA detectors: High background noise and drift baseline- WKB9482

SYMPTOMS

• High background noise
• Drift baseline stepping upward
• Peaks very low (compared to earlier chromatograms on the same system) 
• Lamp is new or it has less than 2000 hours
• Read Energy at 230 nm (water running through flow cell) <5000
• Dynamic leak test passes
• Noise and drift test fails

ENVIRONMENT

• ACQUITY UPLC PDA Detector
• ACQUITY UPLC Tunable UV Detector
• ACQUITY Arc 2998
• 2487 Dual-Wavelength Absorbance Detector
• 2489 UV/Vis Detector
• 2996 PDA Detector
• 2998 Photodiode Array Detector

CAUSE

• Dirty flow cell

FIX or WORKAROUND

Clean flow cell - see How to clean the ACQUITY PDA / TUV Detector flow cell

ADDITIONAL INFORMATION

CAUTION: Cleaning solution must not go through an analytical column or the Mass Spectrometry (MS) equipment.

Remove the MS and analytical column from the flow path before flushing.

Set low flow rate and clean the System overnight. Thereafter, prime the system with standard solvents to waste. Run the system overnight with a low-flow method to flush away the cleaning solution.

Under certain circumstances, use of a 30% phosphoric acid (aqueous) solution may be required, remove the sample and solvent manager bottle filters before proceeding with this procedure - you must flush the system with 100% pure water after this procedure to ensure pH neutral.