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Do You Know the Difference between LOB, LOD and LOQ?



Difference between LOB, LOD and LOQ

There are three types of detection limits mentioned in EP17-A2, namely:

LOB (Limit of blank) is what we usually call the blank detection limit. LOB refers to the highest measurement result that can be measured with a certain probability using blank samples. Please pay attention to a certain probability.

LOD (Limit of detection) is the limit of detection that we usually talk about. It is not a blank sample to detect, but the lowest value that can be measured under certain probability conditions for low concentration analyte samples.

LOQ (Limit of quantification) is what we usually refer to as the limit of quantification. It is also a lower value obtained by testing low concentration analyte samples. The accuracy of this value is required, which is not only to be measured, but also to ensure that the results are accurate.


A specific example is used to further explain that for a test method, its LOB is 6mmol/l, LOD is 8mmol/l, and LOQ is 10 mmol/l For different test results, the report represents different meanings.

5 mmol/l, indicating that there is no analyte, and the concentration is less than 8 mmol/l

7 mmol/l, representing analyte, but cannot be accurately quantified, and the concentration is less than 10 mmol/l

9 mmol/l has two meanings: (1) there is analyte, but it cannot be accurately quantified. The concentration is

less than 10 mmol/l; (2) the result is 9 mmol/l, but you should be careful when interpreting this result. This result is not very accurate

11 mmol/l, the result is 11 mmol/l, and this result is relatively accurate


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