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How to clean the ACQUITY PDA / TUV Detector flow cell - WKB48267

Article number: 48267

OBJECTIVE or GOAL

Clean the ACQUITY PDA / TUV Detector flow cell.

ENVIRONMENT

  • ACQUITY PDA Detector
  • ACQUITY UPLC PDA eλ Detector
  • ACQUITY TUV Detector

PROCEDURE

Clean the flow cell as per ACQUITY UPLC PDA Operator's Overview and Maintenance Guide (715002209)

Summary:

Cleaning the Acquity Light Guiding flow cell 

 

Clean the flow cell when it becomes contaminated with the residues of 

previous runs and also after each detector shutdown. A dirty flow cell can 

cause baseline noise, decreased sample energy levels, calibration failure, and 

other problems. 

• Always flush the flow cell with mobile phase as your initial attempt to 

correct these problems. 

• If there is still no improvement, flush the flow cell with 100% pure 

organic solution. 

Recommendation: 100% acetonitrile. 

• If the problems persist, flush the flow cell with 1% formic acid for 30 

minutes, then flush with water until the formic acid is removed. 

• If flushing with the 1% formic acid solution also fails, perform a system 

acid cleansing flush 

Rule: Always use clean, well-degassed eluents. 

Required materials 

• 1% formic acid 

• Clean, chemical-resistant, powder-free gloves 

• Water (for flushing buffers) 

• Intermediate solvent that is miscible in both the mobile phase and water 

• Stainless steel unions (to replace the column during flushing) 

• Wrench suitable for removing and replacing the column 

To clean the flow cell 

1. In the detector control panel, click (Lamp Off). 

2. Stop the solvent flow and remove the column. 

3. Replace the column with a union or piece of tubing. 

4. If another instrument is downstream of the flow cell outlet, break the 

connection at the other instrument and route the outlet tubing to waste 

while flushing. 

 5. Flush the detector with HPLC-grade water. If the mobile phase is not 

compatible with water, flush with an intermediate solvent first. 

6. Pump an acid wash composition of 1.0% formic in water or 90% 

water/10% organic mixture. Flush the flow cell for minimum of 4 hours 

at a low flow of 0.05 to 0.1 ml/min. Do not exceed 1000 psi (69 bar, 

6895 kPa). 

7. Flush the detector with HPLC-grade water. If the mobile phase is not 

compatible with water, flush with an intermediate solvent first. 

Tip: Remove any other active detectors of instruments from the system. 

8. Reattach the column. 

9. Resume pumping mobile phase. If the mobile phase is not miscible in 

water, first flush with an intermediary solvent. 

A stronger concentration of Phosphoric acid, up to 30% may be used if more aggressive cleaning is needed. If a mass spec is included in the system you may substitute the phosphoric rinse with 25% formic 25% IPA and 50% water. 

 

 

Performing a system acid cleansing flush (note, this is a complete system flush in case the issue is caused downstream of the flowcell) 

 

System contamination can cause the flow cell to become contaminated. If the 

system becomes contaminated, perform a system acid cleansing flush. This 

procedure cleans the binary solvent manager, solvent manager, and flow cell. 

 

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 1L mobile phase reservoir with 100% water. 

4. Fill a 1L mobile phase reservoir with 100% isopropanol. 

Note: The cleaning procedure takes approximately 6 hours once the 

solvents are prepared to remove flow cell contaminants. 

To perform the system acid cleansing flush 

1. Remove the sample and solvent manager bottle filters. 

2. Place all lines A1, A2, B1, B2 seal wash, weak needle wash and strong 

needles 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 backpressure in the system. 

7. Transfer 1 mL of mobile phase to an autosampler vial and place in 

position 1:A,1. 

8. Create an instrument method with the following parameters: 

a. Flow rate = 0.5 mL/min 

b. Gradient composition 50% A1:50% B1 

c. Full loop injection 

9. Make 30 full loop injections from the vial containing the mobile phase. 

Set the run time to 0.5 minutes. 

Notes: This step should take approximately 30 minutes. 

10. Repeat steps 1 through 8 using 100% isopropanol as the solvent. Do not 

pass effluent through optical detector for this wash step. Restrictor 

should be routed to waste. 

11. Repeat steps 1 through 8 using 100% water as the solvent. 

Note: Remove the Seal wash line from the mobile phase bottle prior to 

performing the Phosphoric Acid Wash. 

12. Repeat steps 1 through 8 using 30:70 (v/v) phosphoric acid:water as the 

solvent. 

13. To completely remove all flow cell contaminants, continue pumping the 

phosphoric acid mixture for an additional 3 hours. 

14. Repeat steps 1 through 8 using 100% water as the solvent. 

15. Repeat steps 1 through 8 using 50:50 (v/v) methanol: water as the 

solvent. 

16. Replace the sample and solvent manager bottle filters. 

Note: In the case a mass spec is in the system, A Formic flush with 25%, formic 25% IPA and 50% Water may be used in place of the Phosphoric acid flush. 

ADDITIONAL INFORMATION

id48267, A-30PDA, A-30UV, baseline ripple, UPAPDA, UPARPTUV, UPBINARY, UPC2PDA, UPPDA, UPPDAARC, UPPDAARCB, UPPDA-E, UPPDA-L, UPPDALTC, UPPDATC, UPPPDA, UPPTUV, UPTUV, UPTUVARC, UPTUVARCB, UPTUV-E, UPTUVTC

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