Analysis of Possible Causes

1. The priming valve of the infusion pump is open

2. There is liquid leakage in the system

3. The system is not connected with a backpressure device such as a chromatographic column

4. The check valve is not working properly

5. Pressure sensor malfunction

Analysis of Possible Causes

1. The flow rate set by the infusion pump is too high

2. The liquid path is blocked, such as blockage of the chromatographic column

3. The online filter is blocked

Analysis of Possible Causes

1. Air bubbles enter the interior of the pump head

2. The check valve is not working properly

3. Leakage of the sealing ring in the pump

4. There is a liquid leakage part in the flow path

5. The sink filter is dirty, and air bubbles continuously generate at the filter

6. The solvent bottle is contaminated or there are impurities in the mobile phase

7. Air bubbles are generated when special mobile phases are mixed, such as the mixture of glacial acetic acid and methanol

8. Temperature fluctuation

Analysis of Possible Causes

1. Flow cell contamination, with the flow cell window contaminated

2. Air bubbles in the flow cell

3. Flow cell leakage

4. Mobile phase contamination

5. Chromatographic column contamination or damage

6. Low energy of the detector light source

7. System not reaching equilibrium

Analysis of Possible Causes

1. System not equilibrated

2. Detector temperature fluctuation

3. Mobile phase contamination

4. Leakage in the system

5. Chromatographic column contamination

6. Detector light source failure

Analysis of Possible Causes

1. Air bubbles flowing through the flow cell

2. Poor grounding of the detector

Analysis of Possible Causes

1. Impure mobile phase used

2. Sampling problem

Analysis of Possible Causes

1. Air bubbles in the flow path of the autosampler

2. Leakage of the injection pump

3. Sampling needle blockage

4. Detector light source issue

Analysis of Possible Causes

1. Insufficient sample volume, sample not injected

2. Blockage of the injection flow path or leakage of the injection valve

3. Unstable sample, decomposing

4. Incorrect mobile phase used

Analysis of Possible Causes

1. Mobile phase contamination

2. Tubing contamination, or chromatographic column contamination or flow cell contamination

3. Sample carryover from injection

Analysis of Possible Causes

1. System not well equilibrated

2. Unstable pump pressure, such as air bubbles

3. Temperature fluctuation

4. Chromatographic column contamination

5. Mobile phase contamination

6. System leakage

Analysis of Possible Causes

Chromatographic column malfunction

Analysis of Possible Causes

Excessive sample injection volume or overly concentrated sample

Analysis of Possible Causes

1. Leakage detected

2. No actual leakage, false alarm of the sensor

Analysis of Possible Causes

1. Excessive flow rate

2. Chromatographic column blocked

3. Online filter disc blocked

4. Sinker filter blocked

5. Blockage in other pipelines of the system

Analysis of Possible Causes

1. Mobile phase exhausted

2. Check valve not functioning properly

3. A large number of air bubbles entered the system

Analysis of Possible Causes

1. Leakage detected

2. No leakage, false alarm of the sensor

Analysis of Possible Causes

No sample vial at the target position of the tray

Analysis of Possible Causes

1. Leakage detected

2. No leakage, false alarm of the sensor

Analysis of Possible Causes

Failure of wavelength positioning detection, dirty flow cell

Analysis of Possible Causes

1. The deuterium lamp has been used for more than 2000 hours, and the energy has decreased

2. Air bubbles or dirt in the flow cell

Analysis of Possible Causes

1. The tungsten lamp has been used for more than 2000 hours, and the energy has decreased

2. Air bubbles or dirt in the flow cell

Analysis of Possible Causes

Air bubbles or dirt in the flow cell, failure of deuterium lamp level 0 and level 656 detection during self - inspection