LOD = 3σ/S In my work, σ represents the standard deviation of the blank sample (in mV), and S is the slope (in mV/decade). However, when I solve for LOD, the unit becomes decade (i.e., LOD = x decade). This makes it unclear how to determine the actual concentration in terms of meaningful units, as there’s no direct reference. By the way, my linear fitting is based on log₁₀.