In: Chemistry
13. The following calibration data were obtained for a total organic carbon analyzer (TOC) measuring TOC in water:
Concentration, ug/l |
Number of replicates |
Mean Signal |
Standard Deviation |
0 |
20 |
0.03 |
0.008 |
6.0 |
10 |
0.45 |
0.0084 |
10.0 |
7 |
0.71 |
0.0072 |
19.0 |
5 |
1.28 |
0.015 |
Calculate the calibration sensitivity.
What is the detection limit for this method?
Calculate the relative standard deviation for each of the replicate sets.
Step I
Plot the concentration vs mean signal to get the slope which will be the calibration sensitivity of the TOC analyser.
m = 0.0656
Step II
Detection limit = (k*Sb)/m
Step III
Just put values of Standard deviation and m with k = 2 or 3 based on % of confident interval and calculate the limit of detection.