I am doing a limit of detection experiment with a tryptic digest on a MALDI and need help with the math.
I'm doing a broad range of samples starting from 100 ug/mL to 20 ug/mL.
My question is: if I add only 2 uL of the 20 ug/mL analyte solution into 18 uL of (Buffer/trypsin/etc.) and I do see an adequate number of peaks does that mean my LOD is 20 ug/mL?
Or instead, does this mean my LOD is actually 2 ug/mL? Since I took out only 2 uL of the 20 ug/mL solution which would equate to 40 ng total being added into 20 uL of total volume. 40 ng/20 uL = 2 ug/mL.