Rxi-35Sil MS

Rxi-35Sil MS column

Restek Rxi-35Sil MS GC Columns

Restek Rxi-35Sil MS GC columns are engineered for enhanced mid-polarity selectivity, exceptional inertness, and extremely low bleed—making them ideal for GC-MS applications requiring superior resolution of both polar and nonpolar analytes. Featuring a 35% phenyl, 65% dimethylpolysiloxane stationary phase combined with silarylene reinforcement, Rxi-35Sil MS delivers a powerful balance of polarity, thermal stability, and rugged performance.

The increased phenyl content provides improved separation of aromatic compounds, esters, ketones, pesticides, and complex environmental contaminants, while the strengthened silarylene backbone enables high-temperature operation without excessive bleed. This combination results in cleaner mass spectra, more stable baselines, and improved signal-to-noise ratios across demanding analytical workflows.

The advanced Rxi® deactivation technology ensures excellent peak shape even for active or highly functionalized compounds, supporting trace-level GC-MS quantitation in challenging matrices such as wastewater, soil extracts, food products, petrochemicals, pharmaceutical impurities, and forensics applications. Analysts gain robust retention stability, long column lifetime, and consistent performance through rigorous lot-to-lot reproducibility.

As an authorized distributor of Restek products, Chrom Tech provides Rxi-35Sil MS columns in a variety of dimensions to support EPA, EN, AOAC, and industry-specific GC-MS methods. Their enhanced selectivity, low-bleed performance, and thermal durability make Rxi-35Sil MS a preferred choice for laboratories needing reliable mid-polarity separations with MS-grade sensitivity.
Key Definitions ▸
35% Phenyl, 65% Dimethylpolysiloxane Phase
A mid-polarity stationary phase offering stronger interactions with aromatic and polar compounds. The 35% phenyl content improves selectivity for pesticides, aromatics, esters, ketones, and complex semi-volatiles.
Silarylene Reinforcement
A structural enhancement to the polymer backbone that improves thermal stability, allowing the column to maintain selectivity and low bleed during aggressive high-temperature GC-MS methods.
Mid-Polarity Selectivity
A balance between nonpolar and polar retention characteristics, enabling effective separation of diverse analyte classes, particularly mixtures containing both aromatic and nonpolar components.
Rxi® Deactivation
Restek’s proprietary inert surface treatment that minimizes analyte adsorption, delivering sharp, symmetrical peaks even for reactive or polar compounds in complex sample matrices.
Low-Bleed GC-MS Performance
The reduction of stationary-phase bleed during temperature programming. Low bleed ensures cleaner mass spectra and improved detection limits—critical for high-sensitivity GC-MS applications.
Frequently Asked Questions ▸
What types of applications benefit most from Rxi-35Sil MS?
This column excels in mid-polarity separations such as pesticides, environmental SVOCs, PAHs, pharmaceuticals, fragrances, food contaminants, esters, and aromatics. It is ideal for GC-MS workflows requiring enhanced selectivity and clean baselines.
How does Rxi-35Sil MS compare to Rxi-5Sil MS or Rxi-5ms?
Rxi-35Sil MS has significantly higher phenyl content, providing stronger interactions with aromatic and polarizable compounds. This results in enhanced resolution for aromatics and semi-volatiles compared to the more nonpolar Rxi-5Sil MS and Rxi-5ms phases.
Is Rxi-35Sil MS suitable for high-temperature GC-MS?
Yes. The silarylene-reinforced backbone provides exceptional thermal stability, allowing operation under aggressive oven ramps while maintaining low bleed and selectivity integrity.
What makes this column ideal for trace-level GC-MS analysis?
Its combination of mid-polarity selectivity, ultra-low bleed, high inertness, and superior thermal durability yields clean mass spectra and stable baselines—crucial for low-level detection in complex samples.