Do You Need A Headspace Sampler?
Gas purifiers are essential because they assist in providing a clean gas stream, that may 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 of the column. Gas purifiers are like insurance policies to safeguard the instrumentation along with other analytical columns from several types of contaminants. Still, the gas purifiers will not be able to convert low purity gases into high purity gases. Due to this important factor, it’s important to select the proper grade of gases with different purity levels for proper use in gas chromatographic applications.
Selection of Right Gas Purifier to fit your Applications
Various types of gas purifiers can be found in the market. While some gas purifiers remove just one single specific contaminant, other types remove multiple contaminants simultaneously from the gas stream. You need to think about several factors during the selection process of gas purifiers, considering your specific applications. These factors includes the potential contaminants within 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 used in most the gas chromatography (GC) applications. Oxygen traps are normally packed with metal catalysts. Oxygen is recognized as the most detrimental contaminating gas in every analytical columns. Oxygen is capable of producing irreversible oxidation damage, especially to polar stationary phases. Hydrocarbon traps are usually filled with activated charcoal, that may absorb organic compounds which are bigger than methane. Still, the molecular weight and size of the organic contaminants will have a definite effect on the capability of the hydrocarbon trap to a great extent but it may also think about trap efficiency somewhat.
Activated charcoal possesses a higher capacity to trap larger hydrocarbons that are greater than C4, compared to smaller hydrocarbons, which are lesser than C4. Moisture traps are usually filled with unique molecular sieves. When subjected to extensive heating, the crystalline structures are forced to reduce 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 may also be able to remove gases like skin tightening and, sulfur dioxide, hydrogen chloride, and chlorine or other gases that have effective diameters lesser than water.
Process of Contaminants Affecting Gas Stream
If you want to know how the contaminants affect the gas stream, you have to follow the road that the carrier gas takes to find yourself in the gas chromatograph. This path is applicable for detector fuel gases also. The gases begin from a gas tank or perhaps a special gas generator. The gas travels through long lengths of tubes, pressure gauges, valves, and various other fittings. Every one of these areas is really a potential culprit to introduce contaminants into the gas stream. headspace sampler leads not only in degrading the results of chromatography but additionally shortens the life span 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 will get degraded easily when they face oxygen or moisture, especially at high temperatures. These contaminants will also compromise detector performance. Because 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 when you install the gas purifier in a horizontal position. Gas purifiers are available as compact panels having multiple purifiers or single panel that has multi-absorbent capabilities.
