Standard Addition Feature in SCIEX OS: Should the sample with the actual concentration of “0” be set to unused?

For research use only. Not for use in diagnostic procedures.

Answer

By design it is not recommended to set the sample with an actual concentration of “0” to unused.
The following is the explanation.
The calibration curve in the case of the standard addition workflow is generated using the area, which is the sum of the unknown concentration of the analyte in the matrix and the known concentration of the analyte added to it. Hence, at each concentration level, the unknown concentration is added. Now, considering the unknown sample, which has an actual concentration of “0”, but, it still contains the unknown concentration of the analyte. Hence, it is required to be considered while plotting the calibration curve, as removing it might end up giving the incorrect intercept and, in turn, the incorrect calculated concentration in the sample.