 Limit of detection in the IUPAC Gold Book

DOI10.1351/goldbook.L03540. Official indexed definition verified: concentration or quantity derived from the smallest measure detected with reasonable certainty for a specified procedure; blank mean plus a confidence-dependent multiple of blank standard deviation. Direct historical HTML/PDF retrieval failed, so no full-PDF inspection claimed. The article's equal-variance normal example is an explicitly derived model, not a universal prescribed multiplier.