•The limit of quantitation
LOQ is the smallest conc. at which a
reasonable precision can be obtained (as expressed
by s). The LOQ is obtained by substituting 10 for 3 in the above equation;
• i.e., LOQ = 10sbl /m.
•Ex. In the earlier example
of absorption spectroscopy, the standard
deviation of the blank absorbance for
•10 measurements was 0.0079.
What is the LOD and LOQ?
•sbl = 0.0079; m =
0.0665 ppm-1 ; LOD = 3(0.0079)/(0.0665 ppm-1 ) = 0.36
ppm
•LOQ = 10(0.0079)/(0.0665 ppm-1 ) = 1.2 ppm
•