Gas Chromatography Gas chromatography is widely used in forensic, pharmaceutical, environmental and industrial laboratories. Although considered a fairly robust instrument, with minimal working parts compared to it’s family member the HPLC , a problem or deficiency in any part of the system usually will result in some type of chromatographic difficulty.
Most performance problems can be placed within one of the following areas; baseline disturbances, irregular peak shapes or sizes, retention time shifts, loss of separation or resolution, quantitation difficulties, rapid column deterioration, ghost peaks and broad solvent fronts. It is not uncommon to have more than one of these problems occurring at the same time. This makes a logical and systematic approach to problem solving very important, having a logical and controlled troubleshooting procedure will quickly and accurately identify the source of the problem, a skill that becomes easier with practice.
LC Services provides expert Care, Maintenance and Troubleshooting of Gas Chromatographic systems on a variety of models and detectors.
Common standalone GC detectors:
- (FID) A flame ionization detector consists of a stainless steel jet constructed so that carrier gas exiting the column flows through the jet, mixes with hydrogen, and burns at the tip of the jet.
- An electron capture detector (ECD) consists of a sealed stainless steel cylinder that contains radioactive nickel-63.
- (TCD) A thermal conductivity detector consists of tiny coiled wires arranged in a wheat stone bridge configuration.
- (NPD) The nitrogen-phosphorus detector is similar to the FID, except that the hydrogen gas flow rate is reduced to 1 to 3 milliliters per minute (ml/min), and an electrically heated thermoionic bead is positioned just above the jet orifice.
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Key preventative maintenance procedures - Clean/Check operation of fans
- Clean/Check circuit boards/switches/connectors
- Check pneumatics
- Check Hydrogen/leak and flow test
- Check make up gas/leak and flow test
- Check autosampler alignment & adjust if necessary
- Check sample/flush, syringe replace if necessary
- Check packed injector, leak test and liner replace if necessary
- Check gas sampling valve, leak test and actuator
- Check column & injector, leak test, ramp control, cooling control
- Check output on installed detectors (ie FID, ECD, HND, NPD.)
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FAQ
Q My current supplier can provide replacement injector tower modules can LC Services?
A Yes, we have the ability and resources to provide the same. Immediate exchange modules units, whilst yours is being repaired, is typical of our commitment to delivering maximum ‘uptime ‘and efficiency with minimal fuss.
More FAQs in our ChromaForum
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Gas Chromatography 
