Refractive index-assisted UV/Vis spectrophotometry to overcome spectral interference by impurities

A major challenge hindering the application of techniques like UV/Vis spectrophotometry in determining concentration is spectral interference from contaminants. Since molar absorptivities vary significantly, even minuscule amounts of specific contaminants may cause relatively large errors in UV/Vis spectrophotometry based quantification. Current methods to deal with this are slow, cost-intensive, or ineffective for unknown interferents. We propose constrained refractometry as an expedient technique to aid UV/Vis spectrophotometry, avoiding large errors due to spectral interference. Based on a modified Lorentz Lorenz equation, the technique helps not only in detecting and reducing error from unknown contaminants but also in identifying the significant impurity. Experimental results show a significant reduction of error in concentration determination even for multiple unknown interfering contaminants. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

One major challenge in the application of UV/Vis spectrophotometry for concentration determination is spectral interference from contaminants, which can cause large errors. Current methods to address this issue are often slow and inefficient. Constrained refractometry is proposed as a rapid technique to assist UV/Vis spectrophotometry in reducing errors caused by spectral interference, showing significant improvements in concentration determination accuracy even with multiple unknown interfering contaminants.