Question

Indicate in which of the following measurements has the detection limit been reached? Show wor.

SAMPLE #1:
Analyte Signal: 1.434 ± 0.12
Blank Signal: 01.26 ± 0.09

SAMPLE #2:
Analyte Signal: 2.32 ± 0.09
Blank Signal: 0.33 ± 0.14

SAMPLE #3:
Analyte Signal: 0.85 ± 0.39
Blank Signal: 0.97 ± 0.24

Answer 1

Detection limit (limit of detection - LOD) is the lowest amount of analyte in the sample which can be detected (but not necessarily quantitated).
Blank signal (sample without tested component) can’t be greater than analyte signal.
Therefore, in the sample 3 LOD was reached.