Startup and initialization

Power supply and self-test: Turn on the power supply of each module of the computer and chromatograph in sequence, and wait for the system self-test to complete. If using software such as LabSolutions, double-click the icon to enter the system and connect the device.

Exhaust bubble treatment: Perform exhaust operation in the quaternary pump module to ensure that the mobile phase is free of bubbles. If the instrument has bottle filling function, the mobile phase volume should be set in advance to avoid automatic shutdown caused by solvent depletion.

Mobile phase replacement: Replace the mobile phase according to experimental requirements and thoroughly flush the system.

Method Editing and Parameter Setting

Pump parameters: Set the flow rate in "Flow", set the running time in "Stop time", and edit the gradient elution program through "Timetable".

Injector parameters: Set the injection volume in "Injection" and select the needle washing method.

Column temperature box parameters: Set the temperature control mode, input the target temperature, and ensure the stability of the chromatographic column.

Detector parameters: Select the detection wavelength based on the characteristics of the sample and set the response time.

Sequence Editing and Running

Sequence creation: Edit the sequence in the software, including sample name, location, injection frequency, and calling method.

Automatic shutdown setting: Configure the shutdown mode in the sequence parameters to ensure that the instrument automatically shuts down after the sequence is completed, avoiding prolonged standby.

Data processing and report generation

Standard curve establishment: If there is already a curve, save the method and select the main method module; If you need to create a new curve, click on "Calibration - New Calibration Table", enter the retention time and corresponding concentration.

Report output: Select the data to be printed, right-click to send to the report layout, and select the template to output the results.

2、 Troubleshooting

Abnormal column pressure

Column pressure high:

Reason: Salt deposition in buffer solution or sample contamination.

Solution: Rinse the column with 40-50 ℃ pure water at low speed forward, increase the flow rate after the column pressure drops, and then rinse with room temperature pure water and methanol. If it is sample contamination, rinse the column in reverse with methanol, methanol+isopropanol, methanol, and pure water in sequence.

Low or no pressure on the column:

Reason: misoperation, leakage, or pump failure to provide infusion.

Solution: Check the pump status and exhaust valve; Use filter paper to test the leakage location, tighten the interface or replace the sealing ring; If the solvent inlet filter head is blocked, ultrasonic cleaning or replacement is required.

Retention time changes

Reason: Changes in the composition of the mobile phase, aging of the chromatographic column, fluctuations in column temperature, or abnormal flow rate.

Solution: Review the system settings and reconfigure the mobile phase; Replace the aging chromatographic column; Use a column temperature chamber to stabilize the temperature; Check the pump sealing ring and one-way valve, and replace them if necessary.

Abnormal peak shape

Peak fork:

Reason: Column contamination or column head packing collapse.

Solution: After backwashing the column, rinse with methanol, methanol+isopropanol, methanol, and pure water in sequence; If the filling material collapses, unscrew the column head to clean the hardened part, refill and tighten it.

Frontier peak or inverted peak:

Reason for frontier peak: sample overload or improper solvent selection.

Solution: Dilute the sample or replace the solvent; If the chromatographic column is damaged, replace it with a new column.

Reason for peak inversion: The refractive index of the sample is lower than that of the mobile phase.

Solution: Dissolve the sample in the same solvent as the mobile phase and equilibrate the reference cell before injection.

Baseline drift or noise

Reason: Column temperature fluctuations, uneven mobile phase, or contamination of the flow pool.

Solution: Use a column temperature box to control the temperature; Check the flow matching ratio and degassing situation; Rinse the circulation pool with methanol or 1N nitric acid.

No traffic or abnormal traffic

Reason: System blockage, air ingress, or worn pump seals.

Solution: Segmented inspection of blocked areas, ultrasonic cleaning or replacement; Extract air from the pump outlet using a glass syringe; Replace worn seals.