How to flush blocked UPLC flow cell? - WKB19946

OBJECTIVE or GOAL

How to back flush a flow cell, which is characterized by high pressure in the flow cell.

ENVIRONMENT

• 2475 Multi-Wavelength Fluorescence Detector
• 2487 Dual-Wavelength Absorbance Detector
• 2488 Multichannel Absorbance Detector
• 2489 UV/Vis Detector
• 2996 PDA Detector
• 2998 Photodiode Array Detector
• ACQUITY UPLC Tunable UV Detector
• ACQUITY UPLC PDA Detector
• ACQUITY UPLC PDA eλ Detector
• ACQUITY UPLC FLR Detector

PROCEDURE

1. Remove the column and replace with a union.
2. Unscrew the outlet and inlet lines of the flow cell
3. Connect the mobile phase tubing from the union to the outlet of the flow cell
4. Use suitable solvent (methanol, water, acetonitrile, tetrahydrofuran, DMSO, DMF, or magic mix, depending on your sample and buffer) to backflush the with a low flow rate, such as 0.1 mL/min. Note that the pressure of the flow cell must not exceed 1000 psi.  
5. As the pressure drops, slowly increase the flow rate. A pressure drop indicates that the clog was cleared.
   

ADDITIONAL INFORMATION

For UPLC flow cells, the following procedure can be used for some types of light guided flow cells:

1. If backflushing doesn’t work, try unscrewing the metal fitting at the inlet at the rear of the flow cell.
   
2. A sudden drop of pressure indicates that the flow cell has been flushed successfully.