Residual SORS spectra of Historical Wet Collections

Abstract

Raman spectra discussed in the pubblication "Characterizing Noninvasively Conservation Status of Historical Wet Collections using Spatially Offset Raman Spectroscopy". The dataset consist in 3 different repetition for each sample. Data procesing is explained in detail in the linked paper. Briefly, the glass/container contribution (zero-displacement spectrum) was subtracted from the corresponding offset spectrum to isolate the preservation fluid signature (SORS spectrum). Each SORS spectrum was then compared to the appropriate reference standard fluid (e.g., ethanol 50%–70%, formaldehyde 4%–5%, see Table 1), and subtraction of the reference spectrum was performed to enhance minor spectral contributions. The so called "Residual" Raman spectra are here attached for the four example of historic samples discussed in the paper: (E1) a sample collected by Charles Darwin during the second voyage of HMS Beagle (1831–1836); (E2) a mid-20th century specimen from the former Wellcome Trust collection; (E3) a mixed fish sample from the museum’s “Tank Room,” from the late 20th century; and (E4) experimental preservation material of uncertain provenance and composition, dating from the early- to mid-20th century.