Chromatography - How does flow rate affect peak width?

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SUMMARY

The discussion centers on the impact of flow rate on peak width in chromatography. The lecturer asserts that altering the flow rate does not affect the bandwidth of the peaks, only the retention time of solutes. In contrast, the participant argues that each solute's retention time is uniquely affected by the flow rate, suggesting that the change is compound-specific. The debate highlights the importance of understanding retention time dynamics in chromatography, particularly in relation to flow rate adjustments.

PREREQUISITES
  • Chromatography fundamentals
  • Understanding of retention time and peak width
  • Knowledge of stationary phase interactions
  • Flow rate manipulation techniques
NEXT STEPS
  • Research the relationship between flow rate and retention time in chromatography
  • Explore the concept of peak broadening and its causes
  • Learn about the effects of different stationary phases on solute behavior
  • Investigate methods for optimizing flow rates in chromatographic methods
USEFUL FOR

Chemists, chromatography practitioners, and students studying separation techniques will benefit from this discussion, particularly those interested in the nuances of flow rate effects on chromatographic performance.

CrimpJiggler
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Today in a lecture on chromatography the lecturer gave an explanation which seems pure ******** to me. The example she used was a handful of solutes, each taking a different path through the stationary phase, obviously some paths will be longer than others and thus each solute will have a different retention time. She said that altering the flow rate doesn't alter the bandwidth (the width of the peak), it just shaves an certain amount of time off the retention time for each solute. For example, it shaves 5 seconds off each analyte (regardless of how long their path is) so that the peak moves down the x-axis a bit but doesn't change in width. I'm a visual thinker and my visual image for this concept calls ********. Let's say we have solutes A, B and C and their retention times are:
A = 10s
B = 12s
C = 16s

the way I see it, if I double the flow rate then I will half the retention time for each solute. If I alter the flow rate by a certain amount, then the retention time of each solute will vary depending on their path length. This is a bad example, let's say A, B and C are different compounds with their own specific retention times instead.
If I alter the flow rate by x, my lecturer says that the retention time of each compound will change by y. I say that each compound will change by an amount specific to each compound so the retention time of A will change by ax, B by bx and C by cx, where a, b and c are constants specific to compounds A, B and C. Can anyone here shed light on this? Who is right, me or my lecturer? I kept my mouth shut during the lecture because I couldn't think of the words to convey what I see.
 
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