selectivity for retention time locking.
The resulting exceptionally low-bleed columns are ideal for trace-level GC/MS analysis: with an
Rxi® column, you can chromatograph sub-nanogram levels of active acidic or basic compounds
on the same column— often under the same conditions.
To ensure reproducibility, we redeveloped our manufacturing process tomaximize column-to-
column consistency. Every Rxi® column is individually tested and proven tomeet our stringent
specifications for coating efficiency, selectivity, film thickness, inertness, and bleed. We
guarantee every Rxi® column you receivewill be the best column you have ever used.
Under harshoperating conditions, choose stainless steel MXT® columns:
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Rough handling (e.g., field instruments or process GC).
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Portable instruments / other small ovens requiring tightly coiled columns.
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High temperature chromatography.
When the potential for breakage is high, MXT® columns are your best choice— they present
little risk of spontaneous breakagewhen used at high temperatures or when coiled into small
diameters. While fused silica columns generally cannot be used above 360°C, because the
polyimide outer coating becomes brittle over time at high temperatures, MXT® columns function
well at temperatures exceeding 450°C. With anMXT® column, the only limitation to oven
temperature is the operating limit of the stationary phase.
To prepareMXT® columns, we treat the internal surface of the stainless steel tubingwith our
exclusive Siltek® surface treatment, making the surface as inert as deactivated fused silica. The
Siltek® layer permeates the surface, rather than simply coating it, making the layer
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