Fig. 1
From: Electroreduction of divanillin to polyvanillin in an electrochemical flow reactor
a UV–VIS spectrum of divanillin (7.8 µM) and polyvanillin (equivalent mass to divanillin) in 1 M NaOH recorded on a UV-1650PC Spectrometer (Shimadzu). b Exemplary calibration spectra of high concentrated divanillin solutions (1 M NaOH) in the online UV–VIS setup. c Semi-logarithmic fit of the calibration line in the online UV–VIS setup. Fit function: wavelength [nm] = 380.37 nm + 25.31 nmL/mmol * cdivanillin [mmol L−1]. R2 = 0.9975