2998 Photodiode Array Detector: 2998 Photodiode Array Detector spectrum shows a straight line that did not exist before - WKB89776

SYMPTOMS

• 2998 Photodiode Array Detector spectrum shows a straight line that did not exist before

ENVIRONMENT

• 2695 Separations Module
• 2998 Photodiode Array Detector
• Empower

CAUSE

Unknown

FIX or WORKAROUND

1. Clean the detector
   (1) Remove the column, and directly connect the injector outlet of 2695 and 2998 with a union.
   (2) Run water at 1 mL/min for about 1 hour.
   (3) Run 1:1 isopropanol/acetonitrile for at least 1 hour.
   (4) Run water again.
   Because the maximum pressure rating of the 2998 detector is 1000 psi, the flow rate in step 2 should be set so that the pressure limit is not exceeded.
   After cleaning, run again to check for improvement in the spectrum.
2. Absorbance may be too low, causing baseline fluctuations.
   Extract the chromatogram at the wavelength where the spectrum is linear and compare with when there was no problem.
3. To determine if this is a instrument problem, remove the column and run water to see if it shows a similar shape.
4. Perform 3D Blank Subtraction when processing so that the straight line disappears.

ADDITIONAL INFORMATION