The Ultimate High Performance Fused Silica Capillary Column by Restek features unsurpassed inertness, ultra-low bleed and guaranteed column-to-column reproducibility, which works perfectly with retention time-locking software, according to Restek.

While GC analytical methods have continued to evolve, capillary column technology has been largely unchanged over the last several years. Using new techniques for deactivation, stationary phase synthesis and coating, and tight controls over column manufacturing, Restek has set the benchmark for column performance by introducing the Rxi series.

Rxi columns improve chromatography for many acidic or basic compounds. Surface activity in a column is revealed by the sensitivity and peak shapes for analytes such as 2,4-dinitrophenol (acidic) and pyridine (basic). Sub-nanogram quantities of these compounds are a stringent test of inertness. Rxi columns' unsurpassed inertness allows analysis of acidic or basic compounds under the same conditions.

According to Restek, bleed from Rxi columns is the lowest in the industry, simplifying trace-level analysis with mass spectrometric detectors (MSD, ion trap, etc.), electron capture detection (ECD), nitrogen-phosphorus detection (NPD), or other sensitive detection methods. Columns from each of three manufacturing batches show the reproducibility assured by the new manufacturing process.

In developing Rxi columns, Restek’s first step was to work with its fused silica tubing supplier to establish rigorous controls on internal diameter, outer diameter, ovality, and surface activity. These controls guarantee that the tubing is a known starting point. This uniform tubing is then treated with unique deactivation chemistry, producing a consistent, inert surface on which to apply the polymer. Restek also reformulated the polymers, taking steps to ensure neutrality and to fine tune selectivity for retention time locking. A neutral polymer and a neutral tubing surface are important contributors toward excellent peak shape for both acidic and basic compounds.

Typical applications for the Rxi column series includes: Alcohols, amines, aromatic hydrocarbons, bile acids, drugs, US EPA methods, esters, fatty acid methyl esters (FAMEs), flavors and aromas, glycerides, halogenated hydrocarbons, herbicides, hydrocarbons, organic acids, oxygenates, polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), pesticides, phenols, polymers, solvents, steroids, sugars, sulfur compounds.