I am trying to calculate the LOD of electrochemical sensor, used for heavy metal ions detection. i know , LOD= 3Sb/s , where Sb is the standard deviation of blank solution (without analyte) and s is the slope of calibration curve.
I know how to calculate slope of calibration curve ( peak current of SWV vs Conc. of analyte).
But, i am finding difficulty how to calculate standard deviation of blank solution (i.e. 0.1 M acetate buffer solution (pH=4.5))
please suggest me the detailed process if possible with reference.
will be highly grateful for you all.
If the current and concentration are directly proportional, the LOD of the method would be the mean current of the blanks + 3 times their standard deviation. This would be the lowest value that is statistically different (confidence level of 95%) from the signal of a sample with no analyte. Ref.: https://doi.org/10.1351/goldbook.L03540
Additionally, it seems to me that the first blank could be an outlier, you could apply a Dixon Q test to determine statistically if the current of blank 1 belongs to the population of blanks and remove it if not, obtaining a lower LOD. (https://en.wikipedia.org/wiki/Dixon%27s_Q_test)
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