Liners and O-rings for Agilent GCs
Liners and O-rings for Agilent GCs
Injection port liners have a variety of features to help vaporize the sample so that a true representation of the sample enters the column. Additionally, Agilent liners are individually packaged to maintain cleanliness until used. The part number and lot are silk screened on the liner for quality control and user convenience, and lot tracking is available for quality assurance.
Split injections are intended for use with a split/splitless injection port in gas chromatography analysis. Split liners tend to have a slightly smaller outer diameter to allow for gas flow. For ease of use and reproducibility, the liners have a positioning bead, a restriction to secure the position of the glass wool, and a feature to consistently self-position to the recommended height.
Agilent split liners are made to strict dimension specifications for optimal inlet performance and feature the tightest tolerances for od, id, taper and glass wool placement.
Choose a liner without glass wool if your sample contains nonvolatiles or analytes within a wide boiling range. For unknown samples, use a liner without glass wool to avoid loss of active or labile compounds.
Agilent offers a complete portfolio of liners for your Agilent GC splitless inlet. Our exclusive deactivation is important because of the longer sample/liner contact in splitless mode.
Direct Connect Liners
Agilent's Direct Connect liners provide maximum recovery and minimal decomposition of active compounds for methods requiring splitless injection, such as EPA 8270. They are best for relatively clean samples containing active analytes, such as water extracts. The liners directly connect with the column, similar to press-fit connectors, to aid complete transfer of sample onto the column, eliminating the problem of inlet discrimination and further increasing sensitivity.
Direct connect liners are not designed for the purposes of high volume injections.
2 mm dimpled liner designed to be used in the Agilent MultiMode Inlet (MMI) when analyzing heavy matrix samples such as food or environmental extracts. The liner has been optimized for cold splitless injections and solvent vent injections using the MMI, but it is also compatible with the Agilent split/splitless inlet.
2 mm dimpled liners are not recommended for hot injection because of the small internal volume.
Liner O-rings are used to form a proper seal around the outside of the inlet liner between the inlet weldment and the turn-top. O-rings are composed of either graphite or fluorocarbon material, graphite O-rings are used when operating inlet temperatures exceed 350°C.
Liner Dimensions Driven by Inlet Operation
Well-controlled glass dimensions promote better liner-to-liner consistency, ensuring GC system accuracy and reproducibility. That is why Agilent liners are made to the following precise tolerances:
Outer Diameter (OD)
- Larger od liners fit tightly to improve analyte recovery and limit sample migration onto the inlet’s metal surface. Ideal for splitless injection.
- Smaller od liners are less resistant to carrier and split flow inside the inlet. Best for split injection.
Internal Diameter (ID)
- Ensures that the sample vapor is small enough to fit within the volume of the liner.
- Prevents backflash, sample loss into the septum purge, and split lines – all of which can lower reproducibility and sensitivity.
- Regulates internal volume and ensures proper sealing between the septum and the inlet seal.
- Precise glass bumps on the bottom of the liner allow you to repeatably position the liner relative to the inlet bottom. This is especially critical if you install liners by measuring the distance from the O-ring to the top of the liner.
None Bottom Tapers Dual Tapers
- Straight tubes used in split injection with autosamplers
Directs sample onto head of column and limits analyte exposure to bottom of inlet
Minimizes decomposition and discrimination
Contain sample within glass liner limiting contact with metal inlet surface
Thought to limit loss through septum purge
- Less molecular weight discrimination
- Provides additional surface area for sample vaporization, increasing reproducibility
- Serves as a trap for non-volatiles
For split liners, Agilent specifies the placement of glass wool in the liner so that the syringe penetrates the glass wool, wiping the syringe, to provide the most repeatable results with Agilent autosampler and split/splitless inlet design thermal profile.
Developed for your high sensitivity analyses, Ultra Inert deactivation provides extreme surface inertness – even for liners containing glass wool. Agilent Original deactivation is recommended for your everyday analyses. With use, even deactivated liners become active. Replace the liner regularly.
Agilent Ultra Inert deactivated liners are recommended for samples with active analytes – such as phenols, amines, organic acids, pesticides and drugs of abuse – that could be irreversibly adsorbed on active surfaces in the inlet.