Some Examples of Applications of a Microthermal Desorption Device in the Forensic Laboratory

Abstract: Several applications of a microthermal desorption device for analysis of small forensic samples are presented. The method uses a solid phase microextraction holder with the fiber removed. In addition to samples of inks on paper, this device was successfully used for analysis of toners, various stains on bank notes, and lipstick stains on paper. Other small items encountered in a forensic science laboratory were also analyzed: particles of smokeless powder, particles of coffee, and automotive clear topcoat layer. The desorbed compounds were analyzed by gas chromatography with a flame ionization detector or by gas chromatography–mass spectrometry. This device can be used in connection with any kind of gas chromatograph. By selection of different injector temperatures, fractionated thermal desorption of samples is achieved. The procedure was demonstrated on samples of ballpoint pen ink of various age.