Rxi-Guard

Rxi-Guard column

Restek Rxi-Guard GC Columns

Restek Rxi-Guard columns are highly inert, deactivated guard columns designed to protect and extend the lifetime of your analytical GC or GC-MS column—without introducing dead volume or compromising chromatographic performance. Engineered to match the inertness and deactivation chemistry of Restek Rxi® analytical columns, Rxi-Guard precolumns provide seamless integration and deliver consistent retention, peak shape, and method stability across a wide range of demanding applications.

Installed between the injector and the analytical column, Rxi-Guard columns trap nonvolatile residues, contamination, and matrix components before they reach the primary column. This prevents inlet damage, minimizes analyte adsorption, reduces baseline disturbances, and significantly decreases the frequency of column replacement—especially valuable for complex or “dirty” sample matrices commonly encountered in environmental, forensic, food/flavor, petrochemical, and industrial workflows.

As an authorized distributor of Restek products, Chrom Tech offers Rxi-Guard columns in multiple deactivation chemistries and dimensions to integrate seamlessly with Rxi-1ms, Rxi-5ms, Rxi-1301Sil MS, Rxi-624Sil MS, Rxi-XLB, Rxi-5Sil MS, and other Rxi® columns. Each guard column is manufactured under strict quality control using Restek’s advanced deactivation processes to ensure high inertness, excellent thermal stability, and reliable protection for sensitive GC and GC-MS applications.

Whether used to protect high-value mass spectrometry columns, improve method robustness, or maintain consistent long-term performance across routine analyses, Rxi-Guard columns serve as an essential maintenance and performance tool for any laboratory relying on Restek Rxi® column chemistries.
Key Definitions ▸
Guard Column
A short section of deactivated capillary tubing installed before the analytical GC column. It traps nonvolatile residues and contaminants, preventing damage to the primary analytical column and extending its lifetime.
Dead Volume
Unnecessary internal space within a GC flow path that can cause peak broadening or loss of efficiency. Rxi-Guard columns are engineered to add no measurable dead volume, ensuring sharp peaks and stable retention times.
Deactivation Chemistry
A surface treatment applied inside capillary columns to eliminate active sites that adsorb or degrade analytes. Rxi-Guard deactivation is matched to Rxi® analytical columns to ensure seamless selectivity and inertness.
Matrix Contamination
Nonvolatile sample components (such as lipids, sugars, polymers, residues, or particulates) that can accumulate in the inlet or analytical column, causing performance degradation. Guard columns protect against these contaminants.
GC Inlet Protection
The practice of preventing damaging contaminants from entering the analytical column. Rxi-Guard columns provide effective inlet protection, especially for dirty matrices encountered in environmental, forensic, food, and petrochemical analyses.
Frequently Asked Questions ▸
Why should I use a guard column with my analytical GC or GC-MS column?
Guard columns trap nonvolatile residues, particulates, and reactive contaminants before they reach the analytical column. This prevents damage, improves peak shape stability, reduces maintenance, and significantly extends the overall column lifetime—especially for complex sample matrices.
Does an Rxi-Guard column affect chromatographic performance or add dead volume?
No. Rxi-Guard columns are designed to add virtually no dead volume, ensuring that retention times, resolution, and peak shapes remain consistent. Their matched deactivation chemistry provides smooth analyte transfer to the analytical column.
Can Rxi-Guard columns be used with non-Restek analytical columns?
Yes. While Rxi-Guard columns are optimized for Restek Rxi® analytical columns, they can protect any compatible capillary GC or GC-MS column. However, performance is maximized when paired with matching deactivation chemistries from the Rxi® line.
When should I replace an Rxi-Guard column?
Guard columns should be replaced when contamination buildup begins to affect peak shape, baseline stability, or retention time consistency. In heavy-matrix workflows, replacing the guard column proactively prevents damage to the analytical column and reduces instrument downtime.