How To Get A Fabulous Headspace Sampler On A Tight Budget
Gas purifiers are essential because they assist in providing a clean gas stream, which can guarantee the grade 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 insurance policies to safeguard the instrumentation and other analytical columns from several types of contaminants. Still, the gas purifiers will never be able to convert low purity gases into high purity gases. Due to this important factor, it’s important to select the right grade of gases with different purity levels for proper use in gas chromatographic applications.
Selection of Right Gas Purifier to fit your Applications
Numerous kinds of gas purifiers can be found in the market. Although some gas purifiers remove just one single specific contaminant, other styles remove multiple contaminants simultaneously from the gas stream. You will need to reflect on several factors during the selection procedure for gas purifiers, taking into consideration your unique applications. These factors includes 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 Used 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 filled with metal catalysts. Oxygen is recognized as probably 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, which can absorb organic compounds which are larger than methane. Still, the molecular weight and size of the organic contaminants could have a definite effect on the capability of the hydrocarbon trap to a great extent but it will also think about trap efficiency somewhat.
Activated charcoal possesses an increased capacity to trap larger hydrocarbons that are greater than C4, in comparison to smaller hydrocarbons, which are lesser than C4. Moisture traps are often filled 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 may also be in a position to remove gases like carbon dioxide, sulfur dioxide, hydrogen chloride, and chlorine or other gases that have effective diameters lesser than water.
Procedure for Contaminants Affecting Gas Stream
If you want 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 does apply for detector fuel gases also. The gases start from a gas tank or perhaps a special gas generator. headspace sampler through long lengths of tubes, pressure gauges, valves, and different other fittings. Every one of these areas is a potential culprit to introduce contaminants in to the gas stream. This leads not merely in degrading the results of chromatography but additionally shortens the life of the column of CG.
Major contaminants like oxygen, hydrocarbons, and moisture are capable of 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 may also compromise detector performance. Since the detectors actually ‘see’ these contaminants, the effect is baseline noises, spikes, and drifts.
You should 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 that has multi-absorbent capabilities.