Question

In Figure 20-35, the relative detection limit is 37 after 1sof signal averaging, 12.5 after 10s, and 5.6 after 40 sof signal averaging. Based on the value of 37 at 1 s, what are the expected detection limits at 10 sand 40 sin an ideal experiment?

Short answer

The detection limits expected at 10 s is: 11.7 and the detection limits expected at 40 s is:5.85

Step-by-step solution

Definition of detection limit

• The detection limit is (informally) the lowest analyte concentration that can be consistently identified, and it reflects the precision of the instrumental response obtained by the method when the analyte concentration is zero.

Determine the expected detection limits at  and  in an ideal experiment

The detection limits expected at 10 s is:

$\frac{37}{\sqrt{10}}=11.7$

The detection limits expected at 40 s is:

$\frac{37}{\sqrt{40}}=5.85$