- Pinpointing Performance Problems
- Contacting Restek for Technical Service
- Return Authorization Procedure
Many problems associated with capillary gas chromatography are due to sample contamination or instrument variables. Our technical service chemists may suggest some troubleshooting procedures to isolate these variables. Preliminary troubleshooting efforts by you can help us identify the cause of the problem faster, which will reduce your downtime.
Isolate the Column From Instrument Variables
The first step is to isolate the column from instrument variables. To do this, simply install a new column into the same GC without changing any GC-related variables. We highly recommend keeping a spare column on hand at all times, but if you do not have a spare column, then install the questionable column in another GC that is working properly. If the problem does not seem to follow the column, (i.e., the new column does not work in the same GC, or the old column works fine in another GC), then we suggest performing routine maintenance on the injection port and detector as described in Section II of this installation guide. If the problem seems to follow the column, then it is time to perform routine maintenance on the column as described in Section III of this installation guide. Additional troubleshooting guidance is available in our Guide to GC Column Selection and Optimizing Separations.
Begin Diagramming and Documenting
Document the procedures in chronological order listing times, dates, and important instrument parameters. Label all troubleshooting chromatograms. These steps help to inform anyone else who may be working on the system of the troubleshooting procedures that have been completed. Start with a simple instrument diagram and try switching column A to detector B and vice versa. If the problem moves to detector B, then the problem is most likely occurring in the injector.
If the problem stays on detector A when the column outlet is switched, then suspect a detector problem. Begin isolating detector problems by switching hardware, cables, electrometers, integrators, or any suspect part in the pathway. If the problem goes away from the A side, then that detector is most likely the cause and should be replaced.
Contact our technical service group at www.restek.com/Contact-Us/Technical-Service. Save all chromatograms and notes on any operating parameters.
Provide Restek's Technical Service Chemists with This Information:
- The column's catalog and serial numbers.
- Where and when the column was purchased and the invoice or purchase order number.
- Instrument parameters:
- instrument manufacturer and model number
- injection mode
- attenuation and range setting
- oven temperature profile
- injector and detector temperatures
- detector type
- Sample parameters:
- sample size, list of sample components, and concentrations
- description of the sample components that work and those that are problematic
- derivatization agents, inorganics, or high molecular weight residue which may be present
- number of injections made with the sample on this particular column and the length of time the column has been in service
- Concise description of the problem:
- observed symptoms
- variables affecting the symptoms
- steps taken to solve the problem
- if the problem has been observed before
Before you contact us, obtain chromatograms generated when the column was working properly and chromatograms that illustrate the problem you are having so that we can help you troubleshoot most efficiently.
Procedure for Returning Capillary GC Columns
If we cannot resolve the problem satisfactorily, you can return the column after you obtain a return material authorization number (RMA#) by following our return instructions here.