Guarding your GC Column and Method

This tip aims to remove some stress from managing your GC method by protecting your GC column. Our Zebron Guardian™ columns are an alternative to traditional GC guard columns, negating the need for a union connector between a guard and analytical column, from which many challenges may originate regarding leaks and peaks shape. The Guardian columns are a single continuous length of silica capillary that feature a designated length of stationary-phase preceded by a bare surface of deactivated fused silica. The entirety of the Guardian exterior shares the same protective polyimide coating.

The initial length of bare silica interior is non-retentive and serves as a staging area onto which an injected sample is condensed and focused into a tight band during the beginning of a GC method. Non-volatile and semi-volatile impurities remain on the guard, while the targeted analytes and solvent within the sample volatilize and proceed through the column during the temperate program. A modest length of the guard may then be cut occasionally to remove the accumulation of impurities, spearing the analytical column itself and preserving the column’s performance.

Our Z-Guard columns serve as a traditional guard column that may be connected to any capillary GC column using a “Press-fit Union” or other connective means. A traditional guard does carry the advantage of using different sizes, and perhaps even a guard with a phase, but also presents the challenge of possible active sites and leaks. Specifically, a poor cut among the adjoining columns or a gapped connection will generate poor reproducibility and system shut-downs if they guard is not maintained.