The operation steps of the ultrasonic extractor can be divided into the following three stages:
1、 Preprocessing stage
1. Instrument inspection
Confirm that the power connection is normal, the instrument has no external damage, and all components (transducers, temperature control probes) are securely installed.
Clean the steel tank and inject 1/3~1/2 volume of cold water as the ultrasonic transmission medium, with the water surface higher than the height of the material in the sample container.
2. Sample and solvent preparation
Solid samples need to be crushed and sieved, while liquid samples need to be filtered to remove impurities.
Add extraction solvent in proportion to ensure complete immersion of the sample, with a liquid-solid ratio typically ranging from 10:1 to 30:1.
2、 Core operation stage
1. Parameter settings
Time: Ultrasound time can be set through the panel, and complex samples can be processed in segmented pulses.
Power: Adjust according to the properties of the sample, and reduce the power for easily degradable substances.
Temperature: Open an ice bath or external circulating cooling system for thermosensitive components to maintain a temperature of ≤ 40 ℃.
2. Activate ultrasound
Place the sample container vertically into the steel groove medium, avoiding contact with the groove bottom or side walls.
Press the start button (ON/OFF) and observe the cavitation phenomenon (dense bubbles appearing in the liquid) to confirm normal operation.
3. Process monitoring
Continuous ultrasound should not exceed 15 minutes, and intermittent cooling should be stopped to prevent the medium from overheating (water temperature>60 ℃ needs to be paused).
The viscous sample needs to be shaken halfway to promote uniform dispersion.
3、 Post processing stage
1. Termination and Separation
After the time is up, the machine will automatically shut down, turn off the power, and use tweezers to remove the sample container.
Centrifuge (4000rpm, 5min) or let stand for stratification, collect the supernatant.
2. Purification and Recycling
Combine multiple extraction solutions and recover solvents (such as ethanol) using a rotary evaporator.
Further purify the target component using a solid-phase extraction column (such as HLB).
3. Instrument maintenance
Immediately empty the steel tank medium and dry it, clean the surface residue of the transducer with a soft cloth.
Check the cooling system monthly and replace aging sealing rings.
4、 Key precautions
1. Safety protection: Wear goggles and solvent resistant gloves during operation. Flammable solvents are prohibited in open flame environments.
2. Anti emulsification: If it is difficult to separate the two phases, sodium chloride can be added or short-term centrifugation can be used to break the emulsion.
3. Special samples: Microbial cell fragmentation requires protease pretreatment to avoid excessive ultrasound induced DNA breakage.