Methanol gasoline analysis dedicated chromatographIt is a gas chromatography instrument used for rapid, accurate qualitative and quantitative analysis of the composition of methanol gasoline (a substitute fuel mixed with a certain proportion of methanol in gasoline). It is mainly used in the fields of petrochemicals, quality inspection agencies, gas stations, and new energy fuel research and development to ensure compliance with fuel ratios, stable combustion performance, and environmental indicators.
This chromatograph is based on gas chromatography (GC) technology and is typically equipped with a dual column dual detector system: a polar capillary column (such as PEG-20M or FFAP) is used to effectively separate oxygen-containing compounds such as methanol and ethanol; Another non-polar column (such as SE-30 or DB-1) is used to analyze hydrocarbon components (such as benzene, aromatics, olefins, saturated hydrocarbons, etc.) in gasoline. The detector often uses a hydrogen flame ionization detector (FID), which is sensitive to organic compounds and has a wide linear range. Some high-end models can also integrate thermal conductivity detectors (TCD) for auxiliary analysis.
Methanol gasoline analysis dedicated chromatographMaintenance of key components:
1. Sample injector:
The inner liner of the sampler is prone to contamination and should be cleaned regularly. When cleaning, solvent cotton balls can be used to rinse, and then air dried with atmospheric flow. When the pollution is severe, it is necessary to soak it in the corresponding solvent overnight, then clean it with ultrasonic waves, and finally rinse it with solvent, dry it, and store it in a dryer for later use.
Regularly inspect and replace worn injection pads and O-rings to prevent leaks. The injection spacer can generally ensure that there is no air leakage after 100 injections, and using an airtight syringe for manual injection may reduce the number of uses.
Regularly check the needle core of the injection needle in the automatic sampler to prevent needle jamming caused by wear of the needle core. When the sample solvent is water or the concentrated sample is dirty, the injection needle should be cleaned in a timely manner, and finally repeatedly cleaned with organic solvents such as methanol to avoid water residue in the injection needle and rusting the needle core.
2. Detector:
For flame ionization detectors (FIDs), it is necessary to regularly clean the carbon black and silicon deposits on the collection electrode and nozzle. Acetone or alcohol can be used for cleaning. After cleaning, heat the detector at 70 ℃ for 90 minutes or longer to remove residual solvents. If there are signal burrs on the FID, cleaning should be considered. Remove the various components of the FID according to the instrument manual, clean the nozzle and collection electrode with ethanol, fine sandpaper, etc. After installation, it should be baked at a high temperature of 300 ℃ for 3 hours before ignition, and observe the signal until it stabilizes.
The cleaning and maintenance of other detectors (such as ECD, FPD, NPD, TCD, etc.) should be carried out according to the specific type and manufacturer's recommendations. Usually involves steps such as high-temperature baking, solvent cleaning, and mechanical cleaning.
3. Chromatographic column:
Regularly check the fixation and connection of the chromatographic column to ensure no leakage. After a period of use, if the performance of the chromatographic column deteriorates, it may be considered to re age or replace the column with a new one.
When aging the chromatographic column, it is necessary to age it for 2-4 hours with a carrier gas at a temperature 20 ℃ higher than the daily use temperature (without connecting the detector to avoid contamination). If the column efficiency decreases, the column head can be cut 10-20cm and reinstalled to age.