Identifying Pigment Mixtures in Art Using SERS: A Treatment Flowchart Approach

Abstract

A novel treatment flowchart approach for surface-enhanced Raman scattering (SERS) is used to identify both blue and yellow organic pigments in a single microscopic sample from a series of reference oil paints as well as an actual 18th century oil painting. In particular, several treatment strategies using acids and solvents are integrated into a specific flowchart designed to enable the minimally invasive identification of unknown blue (i.e., indigo, Prussian blue) and yellow organic (i.e., Reseda lake, Stil de Grain, gamboge) pigments in one sample. We demonstrate the first successful identification of a yellow lake pigment in a historic painting using SERS as well as the utility of our treatment flowchart approach for identifying pigments of varying resonance conditions, surface affinities, and treatment requirements in a single microscopic sample from a historic oil painting.

Enhancing polyimide's water barrier properties through addition of functionalized graphene oxide

“…Scattering from the sample was filtered (Semrock, LP02-633RS-25) and focused to the entrance slit of the spectrograph (Princeton Instruments, SP2356, 600 g mm −1 grating blazed at 500 nm). The observed Raman frequencies were calibrated using a cyclohexane standard [38]. The so-called D and G peak intensities (ID and IG) of the Raman spectra peaks of 1350 and 1600 cm -1 respectively, can be related to the integrity of the GO honeycomb carbon lattice.…”

Plasmonic colloidal pastes for surface-enhanced Raman spectroscopy (SERS) of historical felt-tip pens

“…33 In the last six years, Ag colloidal pastes were proposed as an alternative for in situ non-hydrolysis SERS measurements. 6,19,34 This approach consisted of the deposition of concentrated colloidal solution droplets on untreated analytical samples and was particularly effective for the characterization of historical textile bers. However, limitations such as poor spatial resolution, difficulty in achieving homogeneous sample coverage, and consequently poor reproducibility were also identied.…”

Raman Spectroscopy of cultural heritage Materials: Overview of Applications and New Frontiers in Instrumentation, Sampling Modalities, and Data Processing

“…Alternative pre-treatment steps with hydrochloric or sulfuric acid for the identification of yellow, red and blue colorants have also been proposed [143,201,221,222], leading up to a complete flowchart including treatment with acids and solvents to identify blue (i.e. indigo, Prussian blue), and yellow organic (i.e., Reseda lake, Stil de Grain, gamboge) pigments in one sample [263], but these procedures appear more limited in scope.…”