Headspace Sampler On A Budget: 9 Tips From The Great Depression
Gas purifiers are necessary because they help in providing a clean gas stream, which can guarantee the quality of the gas chromatographic analysis and the reliability of the outcomes. Further, such gas purifiers minimize detector noise and prolong the life span of the column. Gas purifiers are like plans to protect the instrumentation and other analytical columns from various kinds of contaminants. Still, the gas purifiers will not be in a position to convert low purity gases into high purity gases. Due to this important factor, it is necessary to select the right grade of gases with different purity levels for proper use in gas chromatographic applications.
Collection of Right Gas Purifier to Suit Your Applications
Numerous kinds of gas purifiers can be purchased in the market. Although some gas purifiers remove just one single specific contaminant, other types remove multiple contaminants simultaneously from the gas stream. You should reflect on several factors through the selection procedure for gas purifiers, taking into consideration your unique applications. These factors will include the potential contaminants present in the gas stream, the limitations on flow and pressure, degrees of gas purity required, desired convenience in replacement of spent gas traps, and space availability.
Common Traps Found in Gas Purifiers
Oxygen, hydrocarbon, carbon dioxide, and moisture traps are the most common purifiers found in most the gas chromatography (GC) applications. Oxygen traps are normally filled with metal catalysts. Oxygen is recognized as the most detrimental contaminating gas in all analytical columns. Oxygen is capable of producing irreversible oxidation damage, especially to polar stationary phases. Hydrocarbon traps are typically filled with activated charcoal, that may absorb organic compounds which are larger than methane. Still, the molecular weight and size of the organic contaminants will have a definite influence on the capacity of the hydrocarbon trap to an excellent extent but it will also reflect on trap efficiency to some extent.
Activated charcoal possesses an increased capacity to trap larger hydrocarbons which are greater than C4, in comparison to smaller hydrocarbons, which are lesser than C4. Moisture traps are usually packed with unique molecular sieves. When subjected to extensive heating, the crystalline structures are forced to lose their hydration or water content. This opens a cavity which gets filled readily with any compound that may fit the cavity. Water fits perfectly into this cavity but this trap will also be able to remove gases like skin tightening and, sulfur dioxide, hydrogen chloride, and chlorine or other gases which have effective diameters lesser than water.
Process of Contaminants Affecting Gas Stream
If you wish to know how the contaminants affect the gas stream, you have to follow the path that the carrier gas takes to get into the gas chromatograph. This path is applicable for detector fuel gases also. The gases start from a gas tank or a special gas generator. The gas travels through long lengths of tubes, pressure gauges, valves, and various other fittings. Each one of these areas is really a potential culprit to introduce contaminants into the gas stream. headspace sampler leads not merely in degrading the results of chromatography but also shortens the life of the column of CG.
Major contaminants like oxygen, hydrocarbons, and moisture can handle wreaking havoc with the columns and detectors of CG. The packed and capillary columns can get degraded easily if they are exposed to oxygen or moisture, especially at high temperatures. These contaminants may also compromise detector performance. Since the detectors actually ‘see’ these contaminants, the effect is baseline noises, spikes, and drifts.
It is advisable to install gas purifiers in a vertical position as wall mounted types to avoid channeling. Channeling occurs once you install the gas purifier in a horizontal position. Gas purifiers are available as compact panels having multiple purifiers or single panel which has multi-absorbent capabilities.