Liquid-liquid extractorIt is the core equipment for sample pretreatment in the laboratory. Daily maintenance should focus on "corrosion prevention, blockage prevention, and accuracy maintenance", combined with its working characteristics of contact with solvents and frequent start stop. The specific maintenance points are as follows:
1、 Basic maintenance after daily use
Cleaning equipment surfaces and contact parts:
Dip a dust-free cloth in ethanol or distilled water, wipe the instrument casing, control panel, and sample stage to remove residual solvents and sample stains (to avoid long-term adhesion of solvents to corrosive materials).
If there is residual sediment in the extraction bottle or separating funnel, soak it in a suitable solvent (such as ethanol or acetone), rinse it, air dry it, and store it. Do not scratch the bottle wall with hard objects.
Pipeline and interface inspection:
After each use, rinse the infusion and extraction channels with distilled water to avoid solvent residue crystallization blocking the pipelines.
Check whether there is leakage at the pipeline interface and sealing gasket. If there is aging or deformation (such as hardening or cracking of the sealing ring), replace the same specification accessories in a timely manner.
Waste liquid and environmental treatment:
Timely clean the waste liquid collection bottle to prevent waste liquid from overflowing and corroding the internal circuits or components of the instrument.
Maintain good ventilation in the laboratory to reduce damage to electronic components caused by solvent evaporation.
2、 Special maintenance of core components
Extraction column/extraction membrane maintenance:
Regularly check whether the filling material of the extraction column is loose or contaminated. If there is blockage or a decrease in adsorption efficiency, replace the column with a new one in a timely manner (matching the model according to the instrument manual).
For membrane extraction components, rinse back with the corresponding solvent after use to remove residual samples on the membrane surface and extend the membrane's service life.
Pump body and valve maintenance:
Check the pipelines of peristaltic pumps and metering pumps monthly for aging and damage, and replace worn pipelines in a timely manner.
Regularly clean the solenoid valve and one-way valve to remove residual impurities inside, ensuring that the valve switches flexibly and seals well (ultrasonic cleaning can be used to dry and assemble).
Heating/cooling module maintenance:
If the instrument has a heating function, clean the surface stains of the heating plate to avoid affecting the uniformity of heating; Check if the temperature sensor is functioning properly. If there is a significant temperature deviation, calibrate it promptly.
The cooling module needs to keep the heat dissipation port unobstructed and regularly clean the dust on the heat sink to avoid a decrease in cooling effect due to poor heat dissipation.
3、 Regular calibration and performance checks
Calibrate key parameters of the instrument every 3-6 months, such as extraction time, speed, and temperature control accuracy, to ensure compliance with experimental requirements (which can be verified through standard sample testing).
Regularly conduct no-load operation tests to observe whether the instrument starts and stops smoothly, whether the movements of various components are coordinated, and whether there are any abnormal noises (if there are abnormal noises, check whether the motor, bearings, and other components are worn).
4、 Maintenance precautions
Liquid-liquid extractorDuring maintenance, it is necessary to turn off the power and disconnect the gas source to avoid the risk of electric shock or solvent leakage.
It is prohibited to use highly corrosive solvents (such as concentrated hydrochloric acid and concentrated nitric acid) to directly clean the instrument body. It needs to be diluted or treated with neutral solvents.
Before long-term use of the instrument, it is necessary to thoroughly clean the pipelines and extraction components, dry them and store them in a sealed manner to prevent dust and moisture from entering the interior.
Replacement of accessories should use original or compatible products of the same specifications. It is prohibited to replace different models of components at will to avoid affecting the performance of the instrument.