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How did we Create the Rxi® Column Family?
We’ve optimized phase chemistry, column deactivation, and our manufacturing process to ensure exceptional performance.
Rxi® Deactivation
• Effectively shields reactive silanols.
• Ensures comprehensive inertness (acids, bases, and diols).
• Provides symmetric peaks for higher sensitivity.
Polyimide
Rxi® Manufacturing
Tighter quality controls for better performance and
reliable column-to-column reproducibility.
Rxi® Phase Chemistry
• Enhances selectivity for challenging separations.
• Increases thermal stability, widening the application range.
• Lowers bleed for MS compatibility.
• Surface bonding increases durability and ensures
reproducible retention times.
Restek® Fused Silica
We make our own tubing to ensure high quality and
an uninterrupted supply!
GC COLUMNS | HIGH-PERFORMANCE Rxi® COLUMNS
Rxi® Columns Overview
Lower Detection Limits with Groundbreaking Column
Technology
Rxi® columns deliver more accurate, reliable trace-level results than any other
fused silica column on the market. To ensure the highest level of performance, all
Rxi® capillary columns are manufactured and individually tested to meet strin-
gent requirements for exceptional inertness, low bleed, and unsurpassed column-
to-column reproducibility.
Highest Inertness
Inertness is one of the most difficult attributes to achieve in an analytical column,
but it is one of the most critical as it improves peak shape, response, and retention
time stability. Rxi® technology produces the most inert columns available, providing
these benefits:
• Increased signal-to-noise ratios to improve low-level detection.
• Reproducible retention times for positive identifications.
• Improved response for polar, acidic, and basic compounds.
Increased Signal and Reproducible Retention Times
When capillaries are not sufficiently deactivated, peaks become asymmetric,
resulting in reduced signal and unpredictable retention times. As column activ-
ity increases, peak tailing becomes more pronounced, reducing peak height and
causing retention time to drift (Figure 1). In practice, this means that sensitivity
is lost and trace-level analytes cannot be reliably determined. In addition, even
compounds at higher concentrations may be misidentified due to retention time
shifting.
A more significant problem for sample analysis is that retention time can vary
with analyte concentration if the column is not highly inert. Since the amount
of target analyte in samples is unknown, retention times on a poorly deactivated
column can easily vary enough to move compounds outside the retention time
window (Figure 2). This can result in inaccurate identifications, the need for man-
ual integration, and additional review or analysis before results can be reported.
Using inert Rxi® columns ensures that compounds elute with good signal-to-noise
ratios at expected retention times, regardless of analyte concentration.
Figure 1: As column activity increases,
signal decreases and retention time
shifts.
Time (min)
High inertness
• Symmetric peaks
• Strong response
• Accurate, low-level detection
Poor inertness
• Reduced sensitivity
• Misidentification
• Incorrect results
Time (min) GC_EX01116
free literature
Rxi® GC Columns
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