Question

Using the following table, calculate the molar extinction coefficient (use slope or gradient)

Tabla 3 Cálculo del coeficiente de extinción. Extinction ONPI uM concentration Absorbancecoefficient 2,48 X 10 0,124 50 uM 75 uM 0,199 2,65X103 0,252 100 uM 2,52X103 200 uM 0,351 1,755X10 300 uM 0,523 1,74X10 400 uM 0,715 1,7875X10 500 uM 0,825 1,65X103

uM = micromolar

Answer 1

According to Beer-Lambert's law: A = $\epsilon$cl

Where 'A' is the absorbance of the solution

'c' is the concentration of the solution

'l' is the path length = 1 cm

Therefore, A = $\epsilon$c -----> Equation 1

The plot of absorbance versus concentration can be drawn as follows.

0.9, 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 100 200 300 400 500 [ON P

The equation of the plot: A = 0.00154[ONP] + 0.07017

Compare the above equation with equation 1, then you will get

The molar extinction coefficient ($\epsilon$) = 0.00154 $\mu$M^-1.cm^-1 = 1.54*10^-3$\mu$M^-1.cm^-1