Spectroscopy and Microspectrophotometry

Xylene(s) NaCl(sat d) NazSOa Sodium hydroxide 5% Petroleum ether Phenoxyethanol Propanol Propylene glycol Pyridine Tetrahydrofuran Water 

Source Wilson, J. D., et al., Differentiation of Black Gel Inks Using Optical and Chemical Techniques, Journal of Forensic Sciences 49 (2004). 

Intensity of methyl stretching indicative of alkyd vs. polyester 

One of the interesting aspects of toner particulates is the difficulty in sample preparation, since toner is a waxy solid before it is bonded to a paper substrate. Heat affixing to a metallic substrate such as foil has been used, along with KBr salt plates. Using heat to affix toner to paper was found not to be an issue, except in isolated cases. As with inks, toners could be grouped on the basis of the polymer resins they contain, such as acrylates, methacrylates, polystyrene, and epoxides and corresponding spectral features. 

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