Our FPLC works with two solutions:
A: 20 mM Tris.HCl, 0.2 M NaCl, pH 7.8
B: 20 mM Tris.HCl, 1.6 M NaCl, pH 7.8
I'm interested in sample volume from 102 mL to 117 mL. The FPLC will have a linear concentration gradient: At 24 mL it will be 75% A and at 144 mL it will be 5% A (the rest is filled up with B).
Now, I have a sample with the whole output between the two indicated points (102 mL and 117 mL, so I have 15 mL in my tube) and would like to calculate the NaCl concentration.