Why matrices matter: investigating dye quantification in listerine® with UV-Visible spectroscopy

While numerous studies have explored the quantification of compounds using UV-Visible absorption spectroscopy, matrix effects are rarely studied. This work, investigates the influence of matrix effects on the spectrophotometric determination of two dyes (Quinoline Yellow and Fast Green FCF) in Listerine®. The concentrations of the dyes are determined using both external calibration and standard addition, with only the latter method compensating for matrix effects. Indeed, significant matrix effects are found in both cases, with a notably stronger influence observed in the quantification of quinoline yellow.