Rxi® fused silica capillary GC columns were designed specifically to be the best columns available, for exceptional inertness, ultra-low bleed, and reproducible retention and selectivity. In addition to outstanding performance, this combination of column characteristics assures Rxi® columns will have long lifetimes. The Restek chemists also have developed a stable, reproducible manufacturing process, so that Rxi® columns will meet your needs every time you install a new column.