comparing multiple sets of measurments

Hello everyone!

I have very little to no knowledge of stats (chemist) and hope that you could help me with the problem I am encountering. In brief:
I have 5 sets of measurments for concentration of compounds, using different methods, as attached below (the list itself is longer)

cpds.PNG :

What would be an adequate statistical test, if any, to determine which method is the best at quantifying my compounds concentrations? (higher concentrations would imply a better method).

Many thanks!

Edited for clarity