The ongoing epidemic pertaining to overdose deaths has been attributed to the synthetic opioid fentanyl due to its use as an adulterant in other, less potent drugs of abuse. Detection of low quantities of fentanyl would, therefore, be extremely useful in a forensic science laboratory. While Raman spectroscopy is particularly effective at distinguishing between classes of drugs, weak signatures can prove difficult when dealing with microscopic samples. Surface-enhanced Raman scattering spectroscopy provides the enhancement necessary to make Raman a viable approach for the detection of small amounts of fentanyl. This work explores the use of a paper-based substrate loaded with silver nanoparticles for the recovery of small quantities of fentanyl in cocaine, where it was identified at a lower limit of 500 ng (∼65 ppm) in mixtures. Linear relationships were investigated between intensity and concentration for diagnostic peaks associated with fentanyl and cocaine, which in turn sheds light on the attenuation of the enhancement intensity as a result of competitive binding to silver nanoparticles. This work demonstrates a potentially simple and qualitative pathway for the forensic analysis of fentanyl as an adulterant in cocaine.

Jazz, the illustrated book by Henri Matisse, is a testament to the vitality of the artist in the last decade of his career. The book consists of twenty illustrations reproduced in 370 copies using a stencil-based printing technique and the same Linel gouaches the artist had used for the original maquettes. This study reports on the comprehensive analysis carried out to identify the pigments in the gouaches used in Jazz by transmitted and reflectance infrared, Raman, SERS, and X-ray fluorescence spectroscopies, and describes the lightfastness of these gouaches as evaluated by microfaedometry. This study also highlights the necessity of a multi-analytical approach for comprehensive identification of artist materials and investigates the suitability of portable and non-invasive techniques. The results were consistent across the three copies investigated: a portfolio in the collection of the Museum of Modern Art in New York and two books in the collection of the Musée National d’Art Moderne in Paris. In total, 39 distinct colors were characterized, with the magenta, pinks, and blues being the most fugitive.

The exhibition Cézanne Drawing at The Museum of Modern Art (MoMA) brought together an exceptional group of works on paper from public and private collections across the globe. Recognizing the inherent light sensitivity of both the paper and watercolors, controlling, and tracking light exposure was central to the exhibition planning. This concern also led to a systematic study of three watercolors in the museum’s collection, Foliage (1895), Study of Trees (1895), and Mont Sainte-Victoire (1902-06), to characterize the watercolor paints used by Cezanne in these works and their sensitivity to light exposure, and to better understand the condition of the drawings based on the palette’s chemistry. Examination and analysis were undertaken non-invasively and micro-invasively with the following techniques: Infrared Reflectography (IRR), Ultraviolet Fluorescence Photography (UVF), Raman and surface-enhanced Raman (SERS) spectroscopies in addition to X-Ray fluorescence analysis on small spots and large areas using portable (p-XRF) and XRF scanning, respectively. The palette for these three watercolor drawings includes lead white, bone black, vermilion, yellow ochre, chrome yellow, emerald green, viridian, cobalt blue, and synthetic alizarin and carmine lakes. Microfade testing (MFT) was performed on the paper support and spots with each identified pigment, and the data acquired was evaluated both for color change (ΔE₀₀) and rate of color change ( $$\frac{\partial \Delta {E}_{00}}{\partial t}$$ ∂ Δ E 00 ∂ t ). Together these techniques inform the future display and loan of these and similarly fugitive watercolors in Cézanne’s oeuvre.

Properly situating Giorgio de Chirico’s metaphysical works within his lifetime is complicated due to incomplete provenances, his practice of deliberately falsifying dates, and the known existence of forgeries. De Chirico’s palette may have altered over time, due to shifts in his personal taste, changes in availability of materials, and innovations in paints; elucidating his palette and variations thereof during his metaphysical period (1911–1919) offers analytical insights that complement traditional connoisseurship when attempting to correctly position a given work within his lifetime. To this end, eleven paintings from his metaphysical period, and two in his metaphysical style but painted in the 1940s and backdated to the 1910s, were analyzed by non-destructive portable X-ray fluorescence spectroscopy. Analysis of some works was further complemented with micro-destructive analysis by scanning electron microscopy coupled with energy dispersive x-ray spectrometry, as well as Raman and Fourier transform infrared spectroscopy. While the grounds of his paintings are variable, his metaphysical palette is consistent and includes: lead white, zinc white, ochres and umbers, magnetite, bone or ivory black, vermilion, chrome yellow, Naples yellow, copper acetoarsenite, chromium oxide green, and Prussian blue. Less commonly used pigments include cerulean blue and cadmium yellow, and the backdated paintings lack lead white and vermilion.