Elemental analysis of Chinese red seal inks on xuan paper by ArF laser-induced plume fluorescence

Abstract

Chemical analysis of Chinese red seal ink on xuan paper is useful for the authentication of Asian artwork. The analysis has to be nondestructive and has to accommodate artworks of all sizes. We use ArF laser-induced plume fluorescence to analyze six commercial Chinese red seal inks on xuan paper. Two nano-second laser pulses are required for the analysis. The first 355 nm laser pulse desorbs a thin layer of the ink to create a plume; the second 193 nm laser pulse induces multi analytes in the plume to fluoresce. Partial-least-square discriminant analysis of the fluorescence spectra unambiguously sorts the six inks while the sampled area is not visibly damaged even under the microscope. The laser probe can handle samples of arbitrary size and shape, is air compatible, and no sample pretreatment is necessary.