In our lab (the Rijkserfgoedlaboratorium in Amsterdam) we study historic dyes with liquid chromatography. The term chromatography derives from the greek words chroma (color) and graphia (writing, drawing or describing). In the early days of liquid chromatography a piece of paper and a solvent was used to separate different dye components in mixtures. The presence of different components was evidenced by different color bands in the paper.
Nowadays we use Ultra High Performance Liquid Chromatography (UHPLC) coupled with a Photo Diode Array (PDA) detector to separate and identify different components in dyes and other samples. In comparison to the historic technique of paper chromatography however, it is not obvious how to extract the color properties of dye components as these are hidden somewhere in the UHPLC-PDA chromatogram and absorbance spectra.
Figure 1. Computed dilution colors (right) from absorbance spectra (left) for an historic methyl-violet dye.
rainbowmaker is an open source Python package based on color physics
that can be used to compute dilution colors for individual dye
components and mixtures from UHPLC-PDA data. This package is developed
out in the open. If you are interested you can follow our ideas under
construction in this documentation and already try out the Jupyter
notebooks
in this repository. Our goal is to make the package available for
installation soon…
Frank Ligterink and Sanne Berbers
See link to documentation.