Flow injection question, how to calculate Dmax

[arj22]

Homework Statement

Heres the question asked:


Consider the above FIA apparatus. Calculate the Dmax (as seen by the detector) for the apparatus assuming that a 300uL injection volume results in no dilution (dispersion) of the injected sample by the sample stream line in this system.



____



I know you guys can't see the apparatus picture , but i just want to know the right formula to use or someone to lead me to the right direction. Cant find anything in my lecture notes.



Thanks in advance.

Homework Equations

no idea

The Attempt at a Solution

no idea

 

[Borek]

Perhaps just a simple mass balance (as in dilution & mixing) will suffice. But that's just a stab in the dark.

--
methods

 

[Blueshift5]

Dear student,

To calculate Dmax in this scenario, we need to use the formula Dmax = V/D, where V is the injection volume and D is the dispersion coefficient. In this case, the injection volume is given as 300uL. To determine the dispersion coefficient, we need to consider the flow rate of the sample stream and the dimensions of the tubing/conduit used in the FIA apparatus.

If the flow rate of the sample stream is known, we can use the formula D = L/(2u), where L is the length of the tubing/conduit and u is the average linear velocity of the sample stream. If the flow rate is not given, we can assume a typical value of 1-2 mL/min for FIA systems.

Once we have the dispersion coefficient, we can plug it into the formula Dmax = V/D to calculate the maximum dispersion expected for a 300uL injection volume. I hope this helps guide you in the right direction. Good luck!