Rxi-5ms

Rxi-5ms column

Restek Rxi-5ms GC Columns

Restek Rxi-5ms GC columns are industry-standard low-bleed, low-polarity columns engineered for exceptional performance in GC and GC-MS analysis. Featuring a 5% phenyl, 95% dimethylpolysiloxane stationary phase, Rxi-5ms offers balanced selectivity, excellent inertness, and rugged thermal stability—making it one of the most widely used columns across environmental, forensic, food safety, pharmaceutical, and petrochemical applications.

The Rxi® deactivation chemistry provides excellent peak shapes, even for challenging active compounds, while the ultra-low bleed characteristics ensure cleaner mass spectra, higher sensitivity, and improved detection limits in GC-MS workflows. These attributes make Rxi-5ms particularly valuable for trace-level quantitation, target/unknown screening, pesticide analysis, SVOCs, drugs of abuse, and impurity profiling.

As an authorized distributor of Restek products, Chrom Tech supplies Rxi-5ms columns in a full range of dimensions optimized to meet regulatory and method-specific requirements, including U.S. EPA, EN, AOAC, USP, and forensic toxicology methods. Analysts benefit from stable retention times, robust lot-to-lot reproducibility, and long operational lifetimes—hallmarks of the Rxi® column family.

With its reliability, broad applicability, and consistent high-performance characteristics, Rxi-5ms is a trusted workhorse column suitable for both routine and high-sensitivity GC-MS applications.
Key Definitions ▸
5% Phenyl, 95% Dimethylpolysiloxane Phase
A low-polarity stationary phase offering balanced selectivity for a wide range of analytes. It is the most widely used GC-MS phase due to its versatility and consistent, predictable retention behavior.
Ultra-Low Bleed
The minimized release of stationary-phase material at high temperatures, resulting in cleaner baselines, higher sensitivity, and improved mass-spectral fidelity—critical for GC-MS workflows.
Rxi® Deactivation
Restek’s proprietary surface treatment that reduces active sites inside the column, enabling sharp, symmetrical peaks for both nonpolar and moderately polar analytes.
General-Purpose GC-MS Column
A versatile column type suitable for an expansive range of applications—environmental testing, forensics, food safety, petrochemicals, pharmaceuticals, and industrial organics—making Rxi-5ms one of the most universally applicable GC-MS columns.
Thermal Stability
The ability of a GC column to maintain performance under high-temperature ramping. Rxi-5ms columns provide robust thermal endurance, supporting aggressive temperature programs without degrading chromatographic performance.
Frequently Asked Questions ▸
What makes Rxi-5ms one of the most widely used GC-MS columns?
Its combination of low bleed, balanced selectivity, excellent inertness, and rugged thermal stability makes Rxi-5ms a go-to solution for a broad range of GC and GC-MS applications from routine analyses to trace-level quantitation.
Which applications benefit most from Rxi-5ms?
Environmental SVOCs, pesticides, forensics and toxicology, food safety testing, petrochemical profiling, solvent screening, pharmaceutical impurities, and general GC-MS screening all benefit from the versatility and sensitivity of Rxi-5ms.
Is Rxi-5ms suitable for high-temperature programs?
Yes. The column provides excellent thermal stability, enabling aggressive oven ramps and extended high-temperature hold times without compromising performance or increasing bleed.
How does Rxi-5ms compare to other 5% phenyl GC-MS columns?
Rxi-5ms provides superior inertness and significantly lower bleed than many traditional 5% phenyl phases, producing more stable retention times and cleaner mass spectra—particularly valuable for trace-level MS detection.