Does water damage GC column?
Will it damage the column? Injecting small amounts of water (solvent) into a non-polar capillary column will not damage the phase; however, this may not be the case for mid and high-polarity columns.
What causes GC column bleeding?
High bleed is one of the most common issues you’ll encounter when doing gas chromatography. Excessive bleed is often caused by something damaging the stationary phase of the column, things like oxygen from a leak or some aggressive component in the sample.
How long do GC columns last?
A related question that we hear quite often is “what is the shelf life of a capillary GC column.” Once again, there are no right or wrong answers and GC columns usually don’t ship with an expiration date on them – but in general, a pretty good guideline guide line is to use the column within about two years to ensure …
Can I inject water into GC?
Water is not a very nice solvent for gas chromatography. Mostly, it’s because it is because water does not interact well with the stationary phases typically used for GC analysis. Generally, you will not get well formed analyte bands at the head of the column after injection.
Why is water bad for GC?
Injection after injection, water molecules will adsorb and build up on the phase and lead progressively to a change of selectivity of the column. In addition, if the phase is not crosslinked properly, the uncrosslinked phase would bleed out with consecutive water injection.
How do you stop a column from bleeding?
Another method to minimize the impact of column bleed is to use a thinner film stationary phase. Because thinner films reduce compound retention, this technique works, providing there is sufficient peak retention or the column temperature can be lowered to compensate for the reduced retention.
What happens when a capillary column is contaminated?
Column contamination is one of the most common problems encountered in capillary GC. Unfortunately, it mimics a very wide variety of problems and is often misdiagnosed as another problem. A contaminated column is usually not damaged, but it may be rendered unusable. There are two basic types of contaminants: nonvolatile and semi-volatile.
What causes peak tailing in GC capillary columns?
Problems with dead volume (peak tailing) may occur with multiple unions. Exceeding a column upper temperature limit results in accelerated degradation of the stationary phase and tubing surface. This results in the premature onset of excessive column bleed, peak tailing for active compounds and/or loss of efficiency (resolution).
What should the oven temperature be for GC capillary columns?
Setting the maximum oven temperature at or a few degrees above the column temperature limit is the best method to prevent thermal damage. This prevents the accidental overheating of the column. If a column is thermally damaged, it may still be functional.
Why are HCl and NH4OH bad for GC capillary columns?
If the water is not or only poorly retained by the column, the residence time of HCl and NH4OH in the column is short. This tends to eliminate or minimize any damage by these compounds. Thus, if HCl or NH4OH are present in a sample, using conditions or a column with no water retention will render these compounds relatively harmless to the column.