FAQs

High conductivity

1. There are high-conductivity crystals in conductivity cell.
Solution: After cleaning the conductivity cell with 1:1 nitric acid, rinse it with deionized water.

2. The eluent is not pure enough.
Solution: changing the eluent.

3. The chromatographic column absorbs high-conductivity substances.
Solution: Washcolumn repeatedly and alternately with eluent and water.

4. Wrong selection of measuring scale
When conducting positive ions analysis, as the eluate's background conductivity is too high, the selection of too low measuring scale will lead to the indication of too high conductivity value. Just choose the measuring scale again.

5. The suppressor is not working
Solution: Check whether the suppressor is powered on.

6. The sample concentration is too high.
Solution: Dilute the sample.

Pressure fluctuation

1. There are bubbles in the pump.
Solution: Counterclockwise loosening exhaust valve of pump exhaust valve, exhausting bubbles.

2. The check valve of pump is polluted or damaged.
Solution: Change the check valve or place it into 1:1 nitric solution for supersonic cleaning.

3. The filter in the eluent bottle is contaminated or blocked.
Solution: Replace the filter.

4. Inadequate degassing of eluent.
Solution: Replace the eluent.

The six-way injection valve is blocked.

Solution: Inspect the clogging place along the flow direction in turn to identify and clear away the clogging.

Frequent overpressure

1. The column filter membrane is blocked.
Solution: Remove the column and unscrew the inlet end. Take out the sieve plate carefully , put it in 1:1 nitric acid and wash it with ultrasonic wave for 30 minutes, then rinse it with deionized water and assemble it back,  reverse assemble the chromatograph for rinsing. Note that the chromatograph can not be connected with the flow path.

2. The six-way injection valve is blocked.
Solution: Inspect the clogging place along the flow direction in turn to identify and troubleshooting.

3. The check valve of pump is blocked.
Solution: Change the check valve or place it into 1:1 nitric solution for supersonic cleaning.

4. Flow route is blocked.
Solution: find out the clogging point according the gradual elimination metho and make replacement.

5. Excessive velocity.
Solution: Adjust the pump to the appropriate flow rate.

6. The highest limit pressure of the pump is set too low.
Solution: Under the work flow of the chromatographic column, regulate the highest limit pressure to be 5 MPa above the current working pressure.

High baseline noise

1. The device does not run for a long time enough as planned.
Solution:Continuous infusion of eluent until instrumentation is stable.

2. There are bubbles in the pump.
Solution: Counterclockwise loosening exhaust valve of pump exhaust valve, exhausting bubbles.

3. The filter of the water inlet pipe of the pump is blocked, producing negative pressure under the suction force and generating bubbles.
Solution: Replacing the filter or placing the filter into 1:1 1M nitric acid to be washed 5min with ultrasonic bath.

4. There are bubbles in the column.
Solution: Use the eluent prepared by deionized water to rinse the column in low speed to remove the bubbles.

5. There are bubbles in the flow path.
Solution: Remove column and exhaust bubbles through water.

6. There are bubbles in the conductivity cell, which cause regular fluctuation of the baseline.
Solution: Flushing conductivity cel, exhausting bubbles

7. Voltage is unstable or interfered with static electrostatic.
Solution: Add a voltage stabilizer and ground the instrument.

High baseline shift

1. The pre-heating time of the device is insufficient.
Solution: Extend the pre-heating time.

2. Flow leakage.
Solution: find out the leakage area and fix it,if it cannot be solved, replace the joint.

3. Voltage is unstable or interfered with static electrostatic.
Solution: Add a voltage stabilizer and ground the instrument.

Low resolution

1. The concentration of the eluent is not proper.
Solution: Choose proper concentration .

2. The flow rate of the eluentis too high.
Solution: Choose proper flow rate of the eluent.

3. Using samples with excessive concentration
Solution: Dilute the sample.

4. Column is contaminated .
Solution: Regenerate or replace the column.

Poor repeatability

1. The injection volume of the sample is not constant.
Solution: Inject sample at the volume more than 10 times of the quantitative ring volume to ensure full injection.

2. The concentration of injected sample is improper.
Solution: Select proper concentration of injected sample.

3. The reagent is impure.
Solution: Replace the reagent.

4. Foreign substances exist in the deionized water.
Solution: Replace the deionized water.

5. The flow changes.
Solution: Find out the reasons of such changes and adjust it to the original condition.

6. The flow route is blocked.
Solution: find out the blocked place, repair or make replacement.

Redundant peaks

1. The reagent is not pure.
Solution: Replace reagents.

2. Deionized water contains impurities.
Solution: Replace deionized water.

No Peak

1. Incorrect installation of conductivity cell.
Solution: Re-install the conductivity cell.

2. Conductivity conductivity cell is damaged.
Solution: Replace the conductivity cell.

3. The pump has no output solution.
Solution: Check the pressure indication to confirm whether the pump works.

Poor linearity

1. Standard solution is contaminated, especially low-concentration samples.
Solution: Re-prepare the solution.

2. Deionized water is impure.
Solution: replace the deionized water.

3. The concentration of the sample is too high or too low, out of the linear range of the device.
Solution: Choose proper range of concentration.

Abnormal current of the suppressor.

Solution: replace the power cord or constant current power supply.

Generation of bubbles in the pump

1. Absorbed gas in the flow route pipe
Solution: when water supply is on, open the exhaust valve of the pump, start the plunger pump and constantly vibrate the filter to fully remove the gas.

2. Too high indoor temperature leading to insufficient degassing of the deionized water.
Solution: Use on-line degassing device.

3. The check valve of pump is polluted or damaged.
Solution: Change the check valve or place it into 1:1 nitric solution for supersonic cleaning.