Questions regarding chromatography
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This post was last edited by lng Elegance on 2016-1-25 at 21:07. After the chromatograph leaves the factory and is used in practice, there are two capillary columns in use. What impact would doubling the length of the pre-separation column have on the separation performance and measurement accuracy?
With an elongated chromatography column, the result should be: better separation and higher precision, but an increased measurement time.
Typical commercial chromatography columns are optimized based on the composition of the sample to be analyzed, taking into account factors such as column length, carrier gas flow rate, operating conditions, separation efficiency, and the analysis accuracy for various components. Doubling the length of the pre-separation column will certainly improve the separation efficiency, but it will reduce sensitivity, increase retention time, and widen the half-peak width. Additionally, the column switching time will need to be adjusted; if backflushing or forward flushing is performed, this time will also change accordingly. They say it has higher precision upstairs, but that’s not necessarily true. If the parameters are not adjusted properly, the accuracy may decrease.
The separation effect will be better, so the measurement accuracy will also increase. However, the timing for activating the column cut-off valve needs to be adjusted; this can be done gradually in laboratory mode. But the analysis time will definitely increase, so you need to discuss this matter with the process team first