Characterization of toners and inkjets by laser ablation spectrochemical methods and Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy

Forensic application of laser-induced breakdown spectroscopy for the discrimination of questioned documents

“…Few reports have demonstrated the application of LIBS for the analysis of writing inks [5,[18][19][20] and only two for printing ink analysis [21,22]. One of these studies reported the use of LIBS and LA-ICP-MS to study the elemental composition of inks from more than 200 pens [5].…”

“…The application of LA-ICP-MS and LIBS for the analysis of printed documents was recently investigated by Trejos et al [21], who reported the characterisation of toners and inkjet inks by laser-based methods and SEM-EDX using different statistical and comparison methods (i.e., ANOVA with Tukey's post hoc test and PCA). The results indicated that SEM-EDX was not suitable for the examination of 12 black inkjet samples since elemental concentrations were below the detection limits for the majority of elements except sulphur, providing only 47.4% discrimination between possible comparison pairs.…”

Elemental Analysis of Printing Inks Using Tandem Laser- Induced Breakdown Spectroscopy and Laser Ablation Inductively Coupled Plasma Mass Spectrometry

“…Table 4 summarizes the optimized parameters for the analysis of offset printing inks. and all the n Ar n Ar isotopic combinations from m/z n + n 72 to 80) were not selected for detection, during the scanning method to prevent detector saturation 11,41 .…”

“…The resolution of the 39 K peak was customized to 0.4amu (atomic mass units) to minimize interferences from Ca and Ar isotopes. For the rest of the elements and their isotopes the default quadrupole resolution of 0.7amu was used 11,41 . The intensity of the elements reflected the concentration of the element in the ink sample.…”

“…The two of the commonly used laser based analytical tools are LIBS and LA-ICP-MS that provide elemental information of inks [7][8][9][10][11][12] .…”