Analyses of trace amounts of dyes with a new enhanced sensitivity FTIR spectroscopic technique: MU-ATR (metal underlayer ATR spectroscopy).
The identification of organic dyes is a challenging task in all the fields such as the forensic and conservation sciences, especially in cases where the amount of sample is extremely small. In this paper we propose a new enhanced FTIR method (MU-ATR metal underlayer ATR spectroscopy), which we believe is the first of its kind, for the analysis of a few ng of dyes. With this method, dyed fiber micro-extracts can be analyzed using a commercial FTIR microscope with a fixed incident angle, obtaining the same separation between the different classes of dyes investigated as we obtained analyzing pure dyes in transmission mode. Moreover, the new enhancement method has been validated on a real sample dated back to the 1893, showing how it can be promising for the analysis of trace amounts of organic substances in artistic samples such as dyes in paintings or textiles, varnishes and organic residues on archaeological objects.
Department of Chemistry, Microchemistry and Microscopy Art Diagnostic Laboratory, University of Bologna, Via Guaccimanni 42, 48121, Ravenna, Italy. Electronic address: s.prati@unibo.it.
S
S
Prati
MeV Technologies LLC, Westport, CT, 06880, USA. Electronic address: milan@mevphotonics.com.
M
M
Milosevic
Department of Chemistry, Microchemistry and Microscopy Art Diagnostic Laboratory, University of Bologna, Via Guaccimanni 42, 48121, Ravenna, Italy.
G
G
Sciutto
Department of Chemistry, Microchemistry and Microscopy Art Diagnostic Laboratory, University of Bologna, Via Guaccimanni 42, 48121, Ravenna, Italy.
I
I
Bonacini
Department of Chemical Engineering, Imperial College London, London, United Kingdom.
S G
SG
Kazarian
Department of Chemistry, Microchemistry and Microscopy Art Diagnostic Laboratory, University of Bologna, Via Guaccimanni 42, 48121, Ravenna, Italy.
R
R
Mazzeo
Dyes; Enhanced FTIR; FTIR microscopy; Metal underlayer ATR spectroscopy; Trace analysis