Waters chromatographic columnThe precautions for use are as follows:

1. Installation and Connection:

Flow direction identification:

Chromatography columns are usually marked with flow arrows and should be installed correctly in the direction of the arrows to avoid recoil.

The connecting pipeline should be matched with the chromatographic column joint to avoid a decrease in column efficiency or leakage due to poor matching.

Initial flushing:

Before installing the new chromatographic column, pure organic solvents (such as acetonitrile or methanol) should be used at low flow rates（Rinse with 0.1 mL/min and gradually increase the flow rate to the standard analysis flow rate to remove impurities from the column and prevent bubbles from entering the detection system.

2. Fluid phase and equilibrium

Mobile phase compatibility:

Before replacing the mobile phase, it is necessary to ensure that the new mobile phase is compatible with the current solvent in the chromatographic column. If the mobile phase contains buffer salts, it needs to be used firstRinse with a mixture of water/organic solvent at 5 times the column volume, and then introduce a buffer mobile phase.

Avoid using high proportion organic phase directly when the salt concentration in the mobile phase is too high, to prevent salt precipitation and column blockage.

Balance time:

Reverse phase chromatography columns require at leastEquilibrium of the mobile phase at 10 times the volume of the column until the pressure stabilizes with the baseline.

3. Operating condition control:

Pressure and flow rate:

To avoid sudden changes in pressure, adjust the flow rate slowly. The flow rate should be adjusted according to the specifications of the chromatographic column to avoid exceeding the limit of the chromatographic column*Maximum allowable pressure.

Temperature management:

To avoid temperature cycling changes, increasing column temperature can reduce system pressure, but it is not advisable to excessively reduce pressure by increasing column temperature.

PH range:

Recommended reverse phase chromatography columnThe pH range is 1-12, but extreme pH conditions (such as pH ≥ 8) can accelerate the hydrolysis of bonded phases and the dissolution of silica gel, requiring a decrease in operating temperature and a shorter operating time.

4. Sample processing

Sample purification:

Impurities in the sample are the main source of chromatographic column contamination. Suggest using solid-phase extraction（Purification of samples using SPE columns or supercritical fluid extraction (SFE) systems.

Sample required0.2 μ m membrane filtration ensures compatibility between the membrane material and the sample solvent, avoiding membrane dissolution and contamination of the chromatographic column.

Solvent selection:

The sample solvent should be compatible with the mobile phase to avoid precipitation or solvent insolubility after injection. It is recommended to dissolve the sample using a mobile phase or a solution with weaker elution strength than the mobile phase to obtain excellent peak shape and detection sensitivity.