column bleed

column bleed

[′käl·əm ‚blēd]
(analytical chemistry)
The loss of carrier liquid during gas chromatography due to evaporation into the gas under analysis.
References in periodicals archive ?
The company claims it uses a proprietary bonding and deactivation procedure that lowers column bleed and reduces activity.
Bowers and Borts argue that the lack of improvement for the QIT when presented with an analyte present in a complex matrix arises because the width of the window for ion admittance to the trap allows matrix or column bleed ions (or both) to enter with the analyte ions.
The result is long column lifetime with excellent peak shape and low column bleed for the best detection limits at high temperatures.
Thus, the ratio of the number of ions from column bleed or matrix background to the number of ions of the compound of interest stays the same at the time that the total analytical signal is decreased.
These advantages combine to give superior performance for routine and trace analysis, with a four fold reduction in column bleed.
Column bleed is characterized by a baseline that rises as the column temperature is increased.
These columns offer both extremely low column bleed and the structural robustness to withstand the rigors of long term high temperature use, resulting in a system that offers the separation performance and column lifetime required to minimize unwanted or unexpected downtime.
Cyano-based columns can exhibit very high column bleed caused by degradation of the stationary phase and resulting in a variety of problems that hinder government-mandated analysis and quantitation of critical trace analytes.