How to perform a phosphoric acid wash - WKB239878

OBJECTIVE or GOAL

Perform a system cleaning with 30% phosphoric acid.

ENVIRONMENT

• Alliance HPLC System
• 2695 Separations Module
• 2695D Dissolution Separations Module
• 2795 Separations Module
• Arc HPLC System
• ACQUITY APC
• ACQUITY APC Isocratic Solvent Manager
• ACQUITY APC Sample Manager - FTN
• ACQUITY Arc
• ACQUITY Arc Sample Manager FTN-R
• ACQUITY UPLC
• ACQUITY UPLC BSM (example; use other modules as needed)
• ACQUITY UPLC Column Manager
• ACQUITY UPLC H-Class
• ACQUITY UPLC H-Class Bio
• ACQUITY UPLC H-Class Quaternary Solvent Manager (QSM)
• ACQUITY UPLC I-Class
• ACQUITY UPLC H-Class PLUS
• ACQUITY UPLC H-Class PLUS Bio
• ACQUITY UPLC I-Class PLUS
• ACQUITY UPLC M-Class
• nanoACQUITY UPLC
• PATROL UPLC Process Analysis System
• ACQUITY UPLC Process Sample Manager
• ACQUITY UPLC PDA Detector
• ACQUITY UPLC Sample Manager 
• ACQUITY UPLC Sample Manager - Flow Through Needle PLUS (SM-FTN PLUS)
• ACQUITY UPLC Tunable UV Detector
• ACQUITY UPLC FLR Detector
• ACQUITY UPLC RI Detector
• ACQUITY Premier
•  

PROCEDURE

To prepare the solvent:
1. Prepare a mixture of 50:50 (v/v) methanol/water as follows:
a. Measure 500 mL of water in a graduated cylinder.
b. In a separate graduated cylinder, measure 500 mL of methanol.
c. Add methanol to water and mix for 5 minutes.
2. Prepare a mixture of 30:70 (v/v) phosphoric acid/water as follows:
a. Measure 700 mL of water in a graduated cylinder.
b. In a separate graduated cylinder, measure 300 mL of phosphoric acid.
c. Add phosphoric acid to water and mix for 5 minutes.
3. Fill a 1-L mobile phase reservoir with 100% water.
4. Fill a 1-L mobile phase reservoir with 100% isopropanol.

To perform the system acid cleansing flush:
1. Remove the sample and solvent manager bottle filters.
2. Place all lines in 50:50 methanol/water.
3. Prime the solvent lines for 5 minutes each.
4. Prime the seal wash.

5. Prime the wash syringes and sample syringe for 4 cycles.
6. Connect a pressure restrictor in the fluid path after the injector, to create 2000-psi back pressure in the system.
7. Transfer 1 mL of mobile phase to an autosampler vial and place it in the sample manager.
8. Make 30 full-loop injections from the vial containing the mobile phase. Set the run time to 0.5 minutes.
9. Repeat steps 1 through 8 using 100% isopropanol as the solvent. Do not pass effluent through the optical detector for this wash step. The restrictor should be routed to waste.
10. Repeat steps 1 through 8 using 100% water as the solvent.
Note: Remove the seal wash line from the mobile phase bottle before performing the phosphoric acid wash.
11. Repeat steps 1 through 8 using 30:70 (v/v) phosphoric acid/water as the solvent.
12. To completely remove all flow cell contaminants, continue pumping the phosphoric acid mixture for an additional 3 hours.
13. Repeat steps 1 through 8 using 100% water as the solvent.
14. Repeat steps 1 through 8 using 50:50 (v/v) methanol/water as the solvent.
15. Replace the sample and solvent manager bottle filters.

ADDITIONAL INFORMATION

Caution: If you are running an MS detector, do not perform the system acid cleansing flush. Instead, call Waters Technical Service.
Caution: Failure to remove the Hastalloy bottle filters will contaminate the flow path.

NOTE: When performing an acid wash on an FTN, there is no need to perform the acid injections because this can lead to transducer failures.