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Gresham Plastic Products (Dongguan) Co., Ltd
Scientific maintenance of small molecule injectors is a prerequisite for avoiding cross contamination
Date: 2025-11-17Read: 3
Small molecule injectors are key equipment for achieving high-precision and low pulsation liquid delivery, widely used in fields such as drug research and development, biological analysis, and environmental detection. Its core advantage lies in the flow control capability of nanoupgrading to micro upgrading, but it is sensitive to pollution, wear, and sealing. Scientific and standardized maintenance of small molecule injectors is a prerequisite for ensuring injection repeatability (RSD<0.5%), extending service life, and avoiding cross contamination.
1、 Basic maintenance after daily use (at the end of each operation)
Flushing flow path:
First, rinse with a solvent compatible with the sample (such as methanol, acetonitrile) for 5-10 minutes;
Clean the residual salt with deionized water or buffer solution to prevent crystal blockage;
Replace water with high-purity organic phase (such as isopropanol) to prevent microbial growth.
Evacuate bubbles: Perform the "infusion+exhaust" procedure to ensure that there is no air resistance in the pump head;
Needle/connector cleaning: Remove the injection needle and clean it with ultrasound or a specialized needle to avoid protein or particle blockage.
2、 Weekly routine maintenance
Check the sealing components:
Observe whether the pump head sealing ring (such as PEEK or ruby seal) is worn, scratched, or leaking;
If there is pressure fluctuation or inaccurate flow, replace the sealing kit in a timely manner;
Lubricating moving parts: Add trace amounts of fluorine lubricating grease (silicone oil is prohibited) to the screw or piston rod driven by the stepper motor;
Verify flow accuracy: Use an electronic balance weighing method (such as 100 μ L water ≈ 0.1g) to verify the actual output volume.
3、 Monthly in-depth maintenance
Disassemble and wash the pump head and one-way valve:
Disassemble the pump chamber, soak it in dilute nitric acid (5%) to remove metal ion deposition, and then rinse it with ultrapure water;
Ultrasonic cleaning of one-way valve ball and seat to ensure flexible opening and closing without jamming;
Check for aging of pipelines: replace PTFE/PEEK pipelines that are hard, discolored, or have loose joints;
Calibrate position sensor: Confirm the accuracy of the piston stroke zero point to avoid cumulative errors.
4、 Quarterly professional maintenance
Replace vulnerable parts: including injection pads, filter screen plates, O-rings, etc. Even if they are not damaged, preventive replacement is recommended;
System stress test: Run for 30 minutes at maximum working pressure to observe for leaks or pressure decay;
Software and firmware updates: Upgrade control programs to fix known bugs or improve compatibility.