1、 Daily basic maintenance
Mobile phase management:Differential refractive index detectorFilter and degas before use (remove bubbles to avoid baseline fluctuations), and prioritize selecting reagents with low viscosity and compatibility with the detector; If the shutdown lasts for more than 8 hours, the pipeline needs to be flushed with methanol/acetonitrile to prevent solvent residue crystallization.
Sample pretreatment: It is necessary to filter (0.45 μ m filter membrane) to remove particulate matter and avoid blocking the flow cell or scratching the detection element.
Cleaning and maintenance: Wipe the detector housing and injection port with a dust-free cloth daily to prevent dust accumulation; The testing room should be kept dry to avoid circuit failures caused by humidity exceeding 80%.
2、 Core component maintenance
Maintenance of circulation pool: Disassemble and clean once a month, using 5% nitric acid or methanol for ultrasonic cleaning (to avoid scratching the pool wall with hard objects); Stop the machine immediately if any leakage is found, check the sealing gasket and replace it to prevent corrosion inside the detector.
Maintenance of optical system: Check the brightness of the light source (such as tungsten lamp) quarterly, and replace it if the baseline drift is severe; If there are stains on the lens, gently wipe it with specialized lens paper dipped in methanol, and do not touch it with your hands.
Pump body and pipeline maintenance: Rinse the pipeline with purified water every week to prevent salt precipitation; Regularly check the one-way valve. If there is unstable pressure, perform ultrasonic cleaning or replace the valve core.
3、 Regular calibration and inspection
Calibration requirements: Calibrate every six months with a standard refractive index solution (such as a known concentration of sucrose solution) to ensure detection accuracy; Record the data after calibration and compare it with historical values to determine performance degradation.
Performance check: Conduct monthly baseline stability testing (30 minutes of idle operation, drift ≤ 0.001RIU/h) and repeatability testing (continuous injection of the same sample 5 times, RSD ≤ 1%), and investigate the pipeline or optical path in case of abnormalities.
4、 Maintenance under special working conditions
High salt/strongly corrosive samples: Immediately rinse with 5 times the volume of purified water after testing, and then seal with methanol to prevent pipeline corrosion.
Long term shutdown maintenance:Differential refractive index detectorDrain the solvent from the pipeline and dry it with nitrogen gas; After turning off the power, put on a dust cover and store in a dry and ventilated environment.