Drop coating deposition Raman (DCDR) spectroscopy of contaminants

Raman spectroscopy is a useful technique to identify small organic molecules, including contaminants. The drop coating deposition Raman (DCDR) is more sensitive than conventional Raman spectroscopy from solution. It is based on Raman measurement from a small drop dried on a hydrophobic surface where studied molecules are preconcentrated. In this paper, DCDR spectra of dried drops of selected contaminants (food contaminant melamine, fungicide thiram, herbicides bentazon and picloram) on the hydrophobic substrate were acquired for the first time, whereas Raman spectra from stock solutions were impossible to obtain under the same experimental conditions. The lowest DCDR detected concentrations were determined as 6.4 mM, 0.31 mM, 20 mM and 2 mM in deposited concentrations for melamine, thiram, bentazon and picloram, respectively. Therefore, DCDR spectroscopy can serve to detect these molecules in concentrations relevant in food/groundwater contaminations. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

DCDR spectroscopy is a sensitive technique for identifying small organic molecules, especially contaminants in food or groundwater. By acquiring DCDR spectra of dried drops on a hydrophobic substrate, it is more sensitive than conventional Raman spectroscopy and can detect harmful substances at very low concentrations.