Просмотр исходного текста страницы Purge and Trap for Autosamplers and Gas Chromatography9604409

Gas Chromatography (GC) is used to evaluate compounds that could be vaporized without decomposing. To analyze these compounds, a gas chromatograph requires an autosampler whose injection mechanism meets the stress in the analysis. When 'abnormal' amounts of Chemical toxins (VOCs) or aroma compounds should be analyzed, a purge and trap autosampler may be the optimal choice.


The Purge and Trap Process
Purge and trap autosamplers are capable of detecting compounds at the cheapest parts per billion (ppb) levels, hence their value for detecting dangerous compounds such as volatile organic, or aroma compounds that may affect the taste or scent of an product. To arrange an example for chromatographic analysis, a purge and trap autosampler performs these process:
Bubbles carry gas with the sample to release the compounds
Sequesters the compounds inside the concentrator
Vaporizes the compounds by heating the concentrator
The vaporized compounds pass in the concentrator to the column-a collection of cylindrical tubing housed within the column oven with the chromatograph-then they get through to the detector, where they may be analyzed. When the analysis is finished, the outcome are shown on an information interface, and can be printed by using a chart recorder.
Selecting the best [http://www.minecraftminecraft.net/profile/coastchange90.html automatic liquid sampler] and trap for Gas Chromatography is a crucial component for that analysis of low-level compounds. Because of the essential nature of the application, choosing an autosampler with the appropriate capabilities is an important concern. When searching for autosamplers that have a purge and trap concentrator, researchers take into account the following criteria before making a purchase order:
Mechanical robustness- When laboratories process large volume samples, they desire an autosampler whose technology can withstand the trials of the sample injection process.
Analytical ability- In choosing an autosampler for that detection of low-level compounds, the bottom line is to select the one that reduces the chance of carryover between samples whenever possible.
Productivity- In purge and trap autosamplers, high productivity is determined by a dual concentrator mode that accommodates liquid and soil samples, and positioning for a large numbers of liquid and soil samples.
Ease of use- A user-friendly interface, intelligent software, and handheld remote control typify an autosampler which is easy to operate.
Simplicity of maintenance- On-board diagnostic checks, on-board real-time flow diagrams, as well as an error tracking and sample log make an autosampler low maintenance.
When an autosampler receives high marks in every of the categories, it can be considered better than your competition.
Conclusion
Gas Chromatography is liable for the security and quality of various substances, from commercial carbonated drinks to natural pond water. To detect 'abnormal' amounts of volatile organic compounds or any other compounds of these substances, a gas chromatograph needs an autosampler which includes a purge and trap concentrator. In most cases, researchers pick the autosampler depending on the criteria above, and sometimes consider buying it employed to cut costs.