In gas chromatography, a sample is introduced to the column of the chromatograph system via an inlet. To reduce the adsorption or decomposition of analytes in the sample, an inlet liner is typically installed inside the inlet. The inlet liner must contain the sample prior to passing the sample to the column, in order to isolate the sample from any active sites inside the inlet that could decompose the analytes in the sample. Inlet liners should also contain or trap involatile materials in the sample to minimize or prevent them from entering the column; the more involatile materials that enter the column, the more frequently the chromatograph system will need to be cleaned, which results in significant operational inefficiencies.
In order to contain the sample, inlet liners have been designed that contain a plug of glass wool that is used to trap involatile materials. While the glass wool plug does trap involatile materials, it is also difficult to chemically deactivate. As a result, compounds will irreversibly adsorb to the glass wool or chemically decompose on its surface. Thus, some inlet liners that are used contain no glass wool; while these liners do not suffer from the drawbacks of those containing a glass wool plug, they are equally deficient because they allow the sample to leave the liner and interact with active sites in the inlet. Inlet liners have also been designed that have a helical path for the sample to travel through. These inlet liners also have drawbacks because any involatile material in the sample will get trapped at the inlet of the helix and act as an adsorptive trap for the remaining analytes in the sample. Thus, these liners typically need to be replaced frequently in order for the chromatograph system to operate cleanly and efficiently.
Thus, there is a need in the art for inlet liners that can contain or trap involatile materials in a sample without blocking the flow of the sample through the inlet liner and thereby decomposing analytes in the sample. There is also a need in the art for inlet liners that can be used for repeated analyses without the need to be frequently cleaned or replaced.