Errata

Abstract

Applied Spectroscopy Practica has identified errors in Eqs. 2 and 6 of the work, "Spectral Barcoding for the Detection of Fentanyl and Fentanyl Analogs Using Raman Spectroscopy", by Phillip G. Wilcox, Deborah M. Stiffler, Andrew J. Walz, James M. Myslinski, and Jason A. Guicheteau [Applied Spectroscopy Practica. 2025. 3(4): 1–9. DOI: 10.1177/27551857251390911].

Equation 2, as published:

σ_{A} = \sqrt{\frac{1}{N} \sum_{i = 1}^{N} A_{i} - μ_{A}}, σ_{B} = \sqrt{\frac{1}{N} \sum_{i = 1}^{N} B_{i} - μ_{B}}

Equation 2 instead should have been:

σ_{A} = \sqrt{\frac{1}{N} \sum_{i = 1}^{N} {(A_{i} - μ_{A})}^{2}}, σ_{B} = \sqrt{\frac{1}{N} \sum_{i = 1}^{N} {(B_{i} - μ_{B})}^{2}}

Equation 6, as published:

σ_{A}^{w} = \sqrt{\sum_{i = 1}^{N} w_{i} (A_{i} - σ_{A}^{w})}, σ_{B}^{w} = \sqrt{\sum_{i = 1}^{N} w_{i} (B_{i} - μ_{B}^{w})}

Equation 6 instead should have been:

σ_{A}^{w} = \sqrt{\sum_{i = 1}^{N} w_{i} {(A_{i} - μ_{A}^{w})}^{2},} σ_{B}^{w} = \sqrt{\sum_{i = 1}^{N} w_{i} {(B_{i} - μ_{B}^{w})}^{2}}

We regret this oversight and thank those who brought this to our attention.