[iliveatyahoo]

My text book tells me that sensitivity = dy/dx where y is the instrumental response and x is the concentration of the analyte, but does not go into further detail.

If I am given the instrumental response is equal to, for example, 0.1 and concentration of analyte is equal to 0.05

How to I work out sensitivity? Is it simply 0.1/0.05? What does this even mean?

I have an exam tomorrow and cannot get my head around this

Any explanation in layman's terms would be greatly appreciated    

[MOTOBALL]

Your dy/dx is simply the slope of a Response vs. Amount (or concentration) plot, measured over the linear part of the plot.

Suppose you are using an HPLC with a UV detector.

If your signal (dy) is 0.1 absorbance units for an analyte injected at (dx) 0.05 mg/mL,

then sensitivity,   S = dy/dx = 0.1/0.05 = 2 absorbance units per mg/mL.

Note that Sensitivity is not dimensionless, it always is stated as response per unit of sample.