\\\\\\\\The core of extending the service life of continuous flow chemical analyzers lies in standardized operation, regular maintenance, and precise protection. It is necessary to combine the instrument structure (such as peristaltic pumps, reaction pipelines, detectors, injection systems, and other key components) and operating characteristics, and develop measures from multiple dimensions such as daily use, regular maintenance, and environmental control. The specific measures are as follows:
1、 Standardize daily operations and reduce human losses
Strictly follow the startup and shutdown process
Before starting up, it is necessary to check whether the pressure of the power supply and gas source (such as carrier gas and gas) is stable, whether the liquid level of the reagent bottle is sufficient (to avoid empty bottles causing wear and tear of the pump body), and whether the waste liquid pipe is unobstructed (to prevent waste liquid from being sucked back and contaminating the pipeline).
After starting up, perform "baseline stabilization" and "pipeline flushing" (rinse with distilled water or blank reagent for 10-15 minutes) before entering sample analysis; Before shutting down, it is necessary to thoroughly rinse the pipeline, reaction tank, and detector flow tank with pure water to remove residual reagents (especially corrosive and oxidizing reagents such as strong acids and heavy metal solutions), in order to avoid long-term residue that may cause pipeline corrosion, blockage, or detector contamination.
Reasonably control operating parameters
Based on the characteristics of the reagent and analysis method, set a reasonable pump speed (to avoid excessive speed causing pipeline stretching and deformation), reaction temperature (not exceeding the rated upper limit of the heating module to prevent heating wire aging), and injection volume (to avoid overloading causing wear on the injection valve seal).
Avoid frequent switching of analysis methods or sudden changes in parameters (such as sudden temperature rise or pump speed adjustment), and reduce the instantaneous load on instrument components.
Standardize sample and reagent processing
The sample needs to be filtered (using 0.45 μ m or 0.22 μ m filter membrane), purified (removing suspended particles and flocculent substances), to prevent particle blockage of the pipeline and wear of the injection valve core; Samples containing high salt and high viscosity need to be diluted before analysis to avoid crystal deposition.
The reagents must meet the purity requirements (such as analytical purity or superior purity), be filtered and stored in the dark after preparation (some reagents such as color reagents are prone to decomposition), and regularly replace deteriorated reagents (such as turbidity and discoloration) to prevent impurities from entering the system.
2、 Regular targeted maintenance to maintain component performance
Maintenance of core vulnerable components
Peristaltic pump: Check the pump tube for aging, cracking, and deformation every week. If there is wear, replace it in a timely manner (it is recommended to replace the pump tube as a whole every 3-6 months, and different channel pump tubes should correspond to different models to avoid mixing); Regularly clean the pump head roller to remove residual reagent crystals and maintain smooth rotation.
Reaction pipeline and connectors: Disassemble the pipeline every month (especially at bends and joints), use a soft bristled brush or a specialized pipeline cleaner to remove any residue on the inner wall, and check whether the pipeline is blocked, aged, or leaking (which can be judged by observing whether the pressure curve fluctuates abnormally); Replace worn sealing rings and connectors (such as PEEK connectors) to prevent reagent leakage from corroding the interior of the instrument.
Sample injection system: Clean the injection valve and sampling needle every two weeks, wipe the outer wall of the sampling needle with an alcohol swab to remove sample residue, and check whether the sealing of the injection valve rotor is good (if there is poor injection repeatability, it may be due to worn seals, which need to be replaced in a timely manner).
Detector: Clean the detector window (such as the quartz window of the UV detector) every month, wipe it with anhydrous ethanol to remove oil stains or reagent residues; Regularly check the energy value of detector light sources (such as deuterium lamps and tungsten lamps), and replace them in a timely manner when the energy decays below 70% of the initial value to avoid affecting detection sensitivity and stability.
Auxiliary system maintenance
Thermostatic/Heating Module: Clean the surface of the heating module quarterly to remove dirt formed by reagent droplets, check the accuracy of the temperature sensor (which can be calibrated with a standard thermometer), and avoid component damage caused by temperature runaway.
Waste liquid and reagent system: Empty the waste liquid tank every week, clean the inner wall of the tank to prevent bacterial growth; Regularly check the sealing of reagent bottle caps, replace aging inlet pipes (to avoid poor liquid absorption), and keep the reagent pipeline free of bubbles (before starting up, exhaust all bubbles in the pipeline to prevent air resistance from affecting the flow rate).
3、 Optimize the operating environment and ensure long-term protection
Control laboratory environmental conditions
The instrument should be placed in an environment with constant temperature and humidity, no corrosive gases, and no strong electromagnetic interference: the temperature should be maintained at 20-25 ℃ (fluctuation ≤± 2 ℃), and the relative humidity should be 40% -60% (to avoid moisture causing circuit short circuits and metal parts rusting); Keep away from equipment such as fume hoods, ovens, centrifuges, etc. (to prevent vibration, heat sources, or corrosive gases).
Avoid direct sunlight on the instrument display screen and circuit control panel to prevent component aging; The laboratory power supply needs to be equipped with a voltage regulator (voltage fluctuation ≤ ± 5%) to prevent unstable voltage from damaging electronic components such as instrument motherboards and detectors.
Maintenance during long-term idle period
If the instrument is not used for a long time (more than 1 month), the pipeline should be thoroughly cleaned and rinsed with anhydrous ethanol (to prevent mold growth), the power and gas sources should be turned off, and the plug should be unplugged; Cover the instrument with a dust cover, place a desiccant (such as silica gel) inside the instrument, and regularly replace the desiccant to keep the interior dry.
Start up and run once a month (with no load or pure water circulation), allowing the pump body, heating module, and other components to run briefly to prevent mechanical parts from jamming and electronic components from getting damp and aging.
4、 Strengthen management and recording, promptly identify hidden dangers
Establish and maintain archives
Detailed records of each startup time, analysis of sample type, maintenance content (such as replacing pump tubes, cleaning pipelines, replacing light sources), fault phenomena and handling methods, tracking component wear patterns through data, and developing replacement plans in advance (such as predicting replacement time based on pump tube usage duration).
Timely handling of minor malfunctions
If any abnormalities are found in the instrument (such as sudden pressure rise, baseline drift, leakage, poor repeatability), the machine should be stopped immediately for inspection to avoid the expansion of the fault. For example, sudden pressure rise may be due to pipeline blockage and needs to be disassembled and cleaned in a timely manner; Leakage may be due to loose joints or worn sealing rings, and components need to be tightened or replaced. Do not operate with faults.
Through the above measures, it is possible to effectively reduce component wear, avoid system pollution, reduce the probability of failure, significantly extend the service life of continuous flow chemical analyzers, and ensure the accuracy and reliability of analytical data.