Calculation of LOD when there is caryover in the blanks

[csousa]

the s/n of the peak in the blank was subtracted from the s/n of the peak in the 0.01% std injection
Is this the typical way to calculate LOD if a peak is observed in the blank injection or should the peak height of the blank have been subtracted from the peak height of the 0.01% std before calculating the s/n?

[Peter Apps]

Welcome to the forum.

the s/n of the peak in the blank was subtracted from the s/n of the peak in the 0.01% std injection
Is this the typical way to calculate LOD if a peak is observed in the blank injection or should the peak height of the blank have been subtracted from the peak height of the 0.01% std before calculating the s/n?

The peak in the blank is noise. If you are going with the usual optimistic S:N > 3 criterion for LOD, then the peak from the standard must be > 3 x (blank peak + baseline noise).

Peter