Check the insertion length of the column and ensure it is in the correct position as specified in the instruction manual for each instrument. Make sure that the column is positioned just below the flame tip (FID) or near the point of detection.

Replace the liner or replace wool. Be careful as wool can break and cause activity; Increase liner temperature.

Cut-off about 50 cm from the injection port side of the column. If still not OK, cut another 50 cm. If not OK, connect detector side to injector and recondition the column for several hours at its maximum operation temperature. If not OK, replace column.

Increase the split ratio.

Check column position in inlet and outlet. If coupling is used check that column ends are correctly cut using the wafer cutting device supplied with the column.

When the component has high polarity, it may show adsorption. If possible, Increase initial oven temperature and use a higher programming rate. Try using a thicker film and/or derivatize the component.

Reduce sample size by smaller injection volume or increase split ratio. Choose a thicker film or a stationary phase where the solvent peak elutes later or earlier then the tailing peak.

Reduce sample size by smaller injection volume or increase split ratio. Use a PLOT column with thicker layer or larger diameter.

Reduce injection volume. Increase split ratio.

Replace O-ring.

Check required length for your instrument and adjust. To secure position especially when a new ferrule is used, slide the column inlet first through a used septum, then put the nut and ferrule on the column, cut 1 cm from the inlet using the ceramic wafer and use the septum to secure the correct insertion depth.

Increase injection port temperature.

Reduce the injection volume and/or increase the split ratio so that it does not exceed the loading capacity of the column. Dilute the sample. Use a column with a thicker film or a wider diameter to increase the sample loading capacity.

Use a stationary phase with better solvability for this component. (For polar compounds, use a polar stationary phase. For non polar compounds, use a non-polar stationary phase

When making a manually injection, the injection speed is unsuitable and/or the syringe is faulty. Replace the syringe or use an autosampler.

Check the insertion length of the column as recommended in the instruction manual for your GC.

This occurs when using splitless injection and on-column injection. Change to a single solvent.

Change either the stationary phase that is compatible with the solvent or use a sufficiently long retention gap to make sure all solvent (droplets) are evaporated in the retention gap.

Check for leaks (use digital leak detection device), around the injection port and column connections. When the inlet septum leaks, replace it. Check how many injections are required before a serious leak of septum develops. Then replace septa after xx injections before the leak develops.

Check initial oven temperature.

Replace the gas selection valve.

Replace or clean flame tip.

When the split vent line becomes blocked, wash or replace it. When the flow control device malfunctions it should be replaced. Replace split line filter. Make this routine maintenance.

Verify the supply pressure to the GC is correct.

Condition the column for several hours at maximum temperature to remove all water and CO₂.

Check for leaks at column connections and carrier gas tubing connections. Check gas filtration systems, replace filters.

Decrease final programmed oven temperature. Use flow programming. Use a more temperature stable phase.

Remove water from the sample. Replace moisture filter for carrier gas. Remove water after each analysis by heating the column to Tmax for 10 minutes. Use a precolumn that retains the water and can be backflushed.

Adjust integration windows. Adjust the flow to get the same retention time. Replace the section that was cut-off with a similar section from a second column or use deactivated fused silica by using a suitable coupling.

Replace the needle or the syringe.

Check the insertion length of the column as recommended in the instruction manual for your GC.

Replace liner. Cut a 2 cm section from inlet, connect column at injector, set flow and check that the column has flow by dipping the column end in a vial with some acetone. Connect detector side and inject methane or a solvent to verify linear gas velocity.

Check that there is a pressure in the injection port. Check for (big) leaks around the injection port and column connections. Also check that septum cap is sufficiently tightened. When there is a leak from the injection port septum, replace the septum. Check the flow rate is correct at the detector outlet and the column outlet.

Check the condition of the detector. Check for broken wire filaments with MS and TCD and check that the FID flame is lit. Check the cable connection between the detector and data acquisition system.

Detector temperature must be set at least 20 degrees higher then final temperature of the oven temperature program.

Wash and/or replace the syringe.

Check column position. Column inlet must be 4–8 mm above the bottom of the liner.

Check for leaks around the injection port. If the injection port septum is leaking, replace the septum.

Reduce the split ratio.

Replace column coupling.

Check the splitless injection parameters and optimize the injection time. Typically injection times are 60–80 seconds.

Check the sample concentration and stability etc. Make sure the sample preparation and storage conditions are suitable.

Check the injection port temperature and optimize it.

Check whether the detector is compatible for detecting the analyte at required levels.

FID: Check the flows for H₂, air and make-up gas. Verify and adjust detector temperature. Clean detector according to manufacturers procedures.

Check that the sensitivity setting of the detector is correct. Check that the attenuation setting is correct for the integration system used.

Check for leaks around the injection port. If the injection port septum is leaking, replace the septum. Check that the supply pressure is correct.

Select a liner and injection volume suitable for the injection method. If injecting manually, pay attention to discrimination. Consider using a liner with some wool for best results. Check column position in the liner.

The amount of sample picked up is not correct. Wash and/or replace the syringe. If the sample viscosity is high, reduce the syringe suction speed.

Replace the liner. Depending on the type of sample and injection technique, select an appropriate liner with or without wool and the appropriate type of wool material.

If the split ratio is too small, the split will not stabilize. Adjust the split ratio so it is suitable for the column and the GC. If short 0.53 mm columns are used, add a few meters of 0.25 mm ID deactivated fused silica as restriction tubing.

Check the detector is working correctly.

Wait until all peaks from the previous run have eluted. To speed up the process, increase the oven temperature and/or carrier gas flow.

Install or replace the gas filtration system.

Replace the liner. Use high-temperature septa with a center guide. Use septum purge. Reduce the injection port temperature. Consider using a Merlin Seal septum.

Use a liner without wool. Reduce the liner temperature. Use PTV or on-column injection.

Replace the O-ring. Condition the liner for 16 hours at 300 °C.

If the syringe is contaminated, wash or replace it. If repeatedly analyzing from the same vial, contamination may occur from material on the outside of the needle as it passes through the septum. Use a larger sample volume in the vial to dilute contamination. When shaking the vial, ensure the liquid does not contact the vial septum. Micropipette tips can release erucamide.

Replace the liner. Inject smaller sample volumes or dilute the sample. Consider using split injection.

Disconnect the split line and rinse it with a solvent similar to that used for the samples, or replace the split line.

Injection volume, liner size, septum purge flow rate, and injection port temperature may cause sample overflow from the liner, resulting in carryover (ghost peaks are the same compounds previously analyzed but now appear as unwanted peaks). Select more suitable injection parameters. Check system cleanliness by running a blank (temperature program only, without injection).

Without carrier gas flow, hydrogen and air can enter the column end, creating highly active sites. Ensure the column is always under positive flow. Stop the flow only after the detector has cooled down. To assess or reduce the effect, decrease the detector temperature. At lower detector temperatures, the ghost peak area should decrease.

The column stationary phase deteriorates rapidly in the presence of oxygen and water, especially at elevated temperatures. Install moisture and oxygen traps in the carrier gas line, positioning them as close to the GC as possible. If filters are already installed, replace them.

Perform a leak test using a digital leak detector. Check all connections, including the septum.

Cut approximately 50 cm from the inlet end of the column. If performance does not improve, cut another 50 cm. If the problem persists, connect the detector end to the injector and recondition the column for several hours at its maximum operating temperature. If still unsuccessful, replace the column. If performance degrades again quickly, improve sample cleanup or use a guard column or precolumn.

Avoid injecting samples containing:

• Inorganic bases (KOH, NaOH, etc.)
• Inorganic acids (HCl, HNO₃, HF, etc.)
• Perfluorinated acids (CF₃COOH, C₂F₅COOH, etc.)
• Salts

These compounds chemically damage both the column and the liner.

If the sample matrix can adversely affect the stationary phase, perform more effective sample pretreatment before injection.

Pay close attention to the final oven temperature in the temperature program and never exceed the column's maximum operating temperature.

Check the carrier gas flow settings and ensure sufficient carrier gas is flowing before heating the column.

Cut approximately 50 cm from the inlet end of the column. If necessary, cut another 50 cm. If the problem remains, reconnect the detector end to the injector and recondition the column for several hours at its maximum operating temperature. If performance still does not recover, replace the column. If deterioration occurs again quickly, improve sample cleanup or install a guard column or precolumn.

• Reduce the elution temperature by using a higher carrier gas flow rate or flow programming.
• Use a slower oven temperature program.
• Use a shorter column with a larger internal diameter (ID).
• Use the thinnest possible stationary phase film.
• Select a stationary phase with lower analyte retention, or combine several of these approaches to minimize residence time in the column.

• Use split injection instead of splitless injection, where appropriate.
• Match solvent polarity to the stationary phase:
  1. Polar solvent → Polar stationary phase
  2. Non-polar solvent → Non-polar stationary phase
• Use a retention gap with the correct polarity.
• Add a co-solvent (e.g., toluene) to reduce droplet formation.
• Use a longer retention gap so that solvent droplets do not reach the analytical column.
• Start the oven at a higher initial temperature to improve solvent focusing.

Perform column conditioning according to the capillary column manufacturer's instructions. Alternatively, condition the column for several hours at a temperature 20 °C higher than your application temperature, without exceeding the column's maximum allowable temperature.

Check the carrier gas purity and filtration system. Inspect all fittings and the septum for leaks.

Running the complete oven program helps condition the column. Injecting smaller sample amounts reduces column bleed formation and extends column lifetime.

The preferred procedure is:

• Reverse the column (connect the detector end to the inlet).
• Condition the column at its maximum operating temperature until the baseline becomes stable.
• Reinstall the column in its original orientation.

Repeat this procedure periodically depending on the amount of high-boiling material introduced into the system.

Clean the detector according to the instrument manufacturer's maintenance procedure.

Column bleed is directly proportional to film thickness.

To reduce bleed:

• Use a thinner film if the separation permits.
• Increase the carrier gas flow for late-eluting compounds so they elute at lower temperatures.
• Reduce the final oven temperature.

As a rule of thumb:

• Increasing carrier gas flow approximately 4× lowers the elution temperature by about 30 °C.
• A 30 °C reduction in elution temperature typically reduces column bleed by approximately 4×.

Replace the inlet liner.

Clean or replace the split vent line (split line) and replace the split line filter.

• Use a higher-quality septum.
• Check for inlet leaks.
• Use septum purge.
• Minimize septum particle generation.

Spikes may occur if the column is inserted too far into the detector port or detector liner.

• Check the column insertion depth.
• Adjust it according to the GC manufacturer's recommended installation length.

Silicone contamination can generate intermittent spikes.

• Clean the detector.
• For an FID, replace the flame tip if necessary.

Electrical signal interruptions can produce spikes.

• Verify that the signal cable is securely connected.
• Inspect the cable insulation.
• Replace the cable if damaged.

An unstable power supply may introduce spike noise.

• Ensure the instrument receives a stable power supply.
• Check the power cord and power source.

Particles released from the stationary phase of a PLOT column can cause spikes.

• Install a particle trap.
• Connect the PLOT column to a 1–2 m silicone-coated fused silica capillary.
• The silicone coating traps particles before they reach the detector.

Detector contamination increases baseline noise.

• Clean the detector.
• Set the detector temperature 20°C higher than the final oven temperature used in the method.

Column contamination results in elevated background noise.

• Cut approximately 50 cm from the injector end of the column.
• If necessary, cut another 50 cm.
• If the problem persists:
  • Reverse the column (connect the detector end to the injector).
  • Condition the column for several hours at its maximum operating temperature.
• If performance does not improve, replace the column.
• If contamination occurs frequently, improve sample cleanup or use a guard column/pre-column.

Contamination in the inlet or liner increases baseline noise.

• Replace the inlet liner.
• Replace the injector septum.

Incorrect installation at the detector can cause noisy baselines.

• Check for leaks.
• Verify the column insertion depth according to the GC instrument manual.

High bleed increases background noise.

• Reduce the final oven temperature.
• Use a column with a thinner film.
• If required, select a column with higher temperature stability.
• Check the gas filtration system and replace gas filters.
• Eliminate water or oxygen contamination in the carrier gas.

Gas leaks contribute to unstable baseline noise.

• Perform a leak check.
• Repair any detected leaks.

Impurities in detector gases increase noise.

• Check filtration for all detector gases.
• Install or replace charcoal filters as needed.

Faulty detector components can generate excessive noise.

• Check detector connections.
• Replace damaged cables if necessary.
• Repair or replace faulty components such as the filament, electron multiplier, amplifier, or baseplate.

Poor detector cable connections may produce unstable signals.

• Verify all detector cable connections.
• Repair or replace defective cables or electronic components.

Nearby equipment (e.g., vacuum pumps) may introduce electrical interference.

• Determine whether the noise occurs only at specific times.
• Switch off nearby instruments one by one to identify the interference source.
• Remove or isolate the offending equipment if possible.

An insufficiently conditioned column can cause baseline instability and recurring ghost peaks.

• Perform the recommended column conditioning procedure.

Contamination along the entire column can result in unstable baselines.

• Condition the column.
• Cut approximately 50 cm from the injector end.
• If necessary, cut another 50 cm.
• If the problem persists:
  • Reverse the column (connect the detector end to the injector).
  • Condition the column for several hours at its maximum operating temperature.
• Replace the column if performance does not recover.
• If contamination occurs frequently, improve sample cleanup or use a guard column/pre-column.

Contamination in the inlet or gas lines may cause oscillating baselines.

• Wash or replace the inlet liner.
• Clean the carrier gas and split gas lines.
• Replace the injector septum.

During oven cooling, stationary-phase degradation products may migrate along one side of the column, causing periodic ghost peaks.

• Use a controlled negative cooling program:
  • Cool the oven at approximately −10 to −20°C/min until the column bleed becomes low.
  • After that point, faster cooling can be used.

Temperature instability, especially with a TCD, may cause baseline oscillation.

• Verify detector temperature stability.
• Ensure the detector temperature controller is functioning correctly.

Fluctuating detector gas flow results in baseline instability.

• Check and stabilize all detector gas flow rates.

Environmental temperature fluctuations may affect detector and baseline stability.

• Verify that the laboratory temperature is within the instrument manufacturer's recommended operating range.
• Minimize drafts and rapid ambient temperature changes around the GC.