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I. Peak loss: Possible causes and troubleshooting methods 1. The syringe is faulty; test it with a new syringe. 2. The detector is not connected, or it is not functioning; check the set values. 3. The injection temperature is too low; check the temperature and adjust it as necessary. 4. The column oven temperature is too low; check the temperature and adjust it as needed. 5. There is no carrier gas flow; check the pressure regulator and look for leaks, as well as verify the flow rate of gas entering the column. 6. The column is broken; if the break occurs at the inlet end of the column or at the end of the detector, it can be repaired by cutting off the damaged portion and reinstalling the column ； II. Frontal peaks 1. Column overload – reduce the sample volume. 2. Co-elution of two compounds: increase sensitivity and reduce the sample volume; lower the temperature by 10–20 degrees to separate the peaks. 3. Sample condensation – check the injection port and column temperature; raise the temperature if necessary. 4. Sample decomposition – use an deactivated injector liner or lower the injector temperature. III. Tailing peaks 1. Active sample adsorption on the injector liner or column: replace the liner. If the problem is not resolved, remove 1–2 turns from the inlet end of the column and reinstall it. 2. The temperature of the column or injector is too low: increase the temperature (do not exceed the column’s maximum temperature). The injector temperature should be 25 degrees higher than the highest boiling point of the sample. 3. When two compounds elute together: increase sensitivity, reduce the sample volume, and lower the temperature by 10–20 degrees to separate the peaks. 4. Column damage: replace the column. 5. Column contamination: remove 1–2 turns from the inlet end of the column and reinstall it. Solutions to common problems in capillary analysis. IV. Only a solvent peak appears: 1. There is a problem with the syringe: test it using a new syringe. 2. Incorrect carrier gas flow rate (too low): Check the flow rate and adjust it if necessary. 3. Sample is too dilute: Inject a known sample to obtain good results. If the results are good, increase the sensitivity or the injection amount. 4. Excessively high column box temperature: Check the temperature and adjust it as necessary. 5. The column fails to separate components from the solvent peak: Replace the column with one having a thicker coating or a different polarity. 6. Carrier gas leakage: Check for leaks (using soapy water). 7. The sample is adsorbed by the column or the injector liner: Replace the liner. If the problem cannot be resolved, remove 1–2 turns from the inlet end of the column and reinstall it. V. Wide solvent peak: 1. A dead volume is formed at the injection port due to improper column installation: reinstall the column. 2. Poor sampling technique (too slow sampling): Use a fast and steady sampling technique. 3. The injector temperature is too low: Increase the injector temperature. 4. Interaction between sample solvent and detection (dichloromethane/ECD): Replace the sample solvent. 5. Residual sample solvent in the column: Replace the sample solvent. 6. Improper cleaning of the gasket: Adjust or clean it. 7. Incorrect split ratio (insufficient split exhaust flow rate): Adjust the flow rate. 6. Spurious peaks: 1. The column adsorbs the sample and then desorbs it: Replace the liner; if this does not solve the problem, remove 1–2 turns from the sample inlet end of the column and reinstall it. 2. Syringe contamination: Try using a new syringe and clean solvent; if the false peak disappears, rinse the syringe several times. 3. Excessive sample volume: Reduce the injection volume. 4. Poor sampling technique and slow sampling speed: Use a fast and steady sampling technique. 7. Unresolved peaks appear in columns that previously worked well. 1. Incorrect column temperature: Check and adjust the temperature. 2. Incorrect carrier gas flow rate: Check and adjust the flow rate. 3. The sample injection volume is too large: Reduce the sample injection volume. 4. The injection technique is poor (injection is too slow): Use a fast and steady injection technique. 5. Column and bushing contamination: Replace the bushing. If the problem cannot be resolved, remove 1–2 turns from the inlet end of the column and reinstall it. 8. Irregular or unstable baseline: 1. Column leakage or contamination: Replace the liner. 2. Detector or injector contamination: Clean the detector and injector. 3. Carrier gas leakage: Replace it