Rxi-PAH

Rxi-PAH column

Restek Rxi-PAH GC Columns

Restek Rxi-PAH GC columns are engineered specifically for high-resolution separation of polycyclic aromatic hydrocarbons (PAHs), delivering industry-leading performance for environmental testing, food safety, and petroleum analysis. Featuring a proprietary mid-polarity stationary phase optimized for PAH selectivity, Rxi-PAH columns provide exceptional resolution of critical isomers—including high-priority EPA and EU regulated PAHs that are notoriously difficult to separate on standard GC phases.

The column’s unique phase chemistry enhances aromatic π–π interactions, enabling precise separation of structurally similar PAHs such as benzofluoranthene isomers, chrysene/triphenylene, benzo[a]pyrene, dibenzopyrenes, and other high-molecular-weight compounds. Combined with Restek’s advanced Rxi® deactivation technology, Rxi-PAH columns produce sharp, symmetrical peaks for both low- and high-boiling PAHs with reduced tailing and improved sensitivity.

Rxi-PAH columns also exhibit extremely low bleed, even at elevated temperatures, which is essential for GC-MS workflows requiring clean baselines and reliable trace-level quantitation. Their rugged thermal stability and excellent lot-to-lot reproducibility support consistent results across EPA 610, EPA 625, EU PAH 15/16 lists, and complex environmental or petrochemical matrices.

As an authorized distributor of Restek products, Chrom Tech provides Rxi-PAH columns in multiple lengths and internal diameters, ensuring compatibility with regulatory methods and high-sensitivity MS detection. Rxi-PAH is the ideal choice when accuracy, reliability, and maximum isomer separation are essential for PAH analysis.
Key Definitions ▸
Polycyclic Aromatic Hydrocarbons (PAHs)
A class of multi-ring aromatic compounds produced by incomplete combustion. Many PAHs are carcinogenic and tightly regulated by EPA and EU methods, requiring precise chromatographic resolution for accurate quantitation.
π–π Interaction Selectivity
A chromatographic retention mechanism where aromatic rings interact through electron cloud stacking. This enhances resolution of PAH isomers and structurally similar aromatic compounds.
High-Molecular-Weight PAHs
Larger, more complex PAHs with higher boiling points, such as benzo[a]pyrene and dibenzopyrenes. Rxi-PAH columns are optimized to resolve these difficult analytes with excellent peak shape and reduced thermal tailing.
Rxi® Deactivation
Restek's proprietary surface treatment that improves inertness, reduces adsorption of active PAHs, and delivers sharp, symmetrical peaks for low- and high-boiling compounds.
Isomeric Resolution
The ability to separate compounds with identical molecular formulas but different structural arrangements. Rxi-PAH excels at resolving critical PAH isomers such as benzofluoranthenes, chrysene/triphenylene, and dibenzopyrenes.
Frequently Asked Questions ▸
What makes the Rxi-PAH column better than standard 5% phenyl or nonpolar GC columns?
Rxi-PAH features specialized PAH-selective chemistry optimized for π–π interactions and high-MW compounds. This improves resolution of regulated PAH isomers that cannot be reliably separated on general-purpose phases like Rxi-5ms or Rxi-1ms.
Which methods commonly require an Rxi-PAH column?
Rxi-PAH is ideal for EPA 610, EPA 625, EU PAH 15/16 lists, food contaminant testing, environmental monitoring, petroleum product characterization, and any workflow requiring high-resolution PAH isomer separations.
Is Rxi-PAH suitable for GC-MS analysis?
Yes. Its extremely low bleed and strong inertness produce cleaner mass spectra, better signal-to-noise ratios, and more reliable quantitation of both low- and high-MW PAHs.
Can the Rxi-PAH column separate benzofluoranthene isomers?
Yes. Rxi-PAH is engineered specifically to resolve benzofluoranthene b/j/k isomers, as well as other critical PAH structural isomers such as chrysene/triphenylene and dibenzopyrenes—without requiring multidimensional GC.