Microscopical reflection-absorption by infrared spectroscopy (R-A IR) was shown as a viable technique for analyzing the polymer resins contained in dry, black photocopy and printer toners. The sampling technique involves a heat transfer of the toner from a document to the reflective surface of aluminum foil followed by analysis by R-A IR. The technique is simple, fast, and readily available to most forensic laboratories. A searchable spectral library was created that contains 807 toner samples analyzed by R-A IR. Ninety-eight groups were established based on spectral characteristics, and a flowchart was developed to assist with group assignments. A blind study was conducted to compare twenty photocopied documents each paired to a test document to determine if the pair could have been produced from the same copier. The analyst obtained 100% correct results in this study. Tests on thirty samples with the spectral library produced 90% first hits for the correct group. The three remaining samples were correctly determined by visual comparison of spectra for the top three hits. An actual case study was conducted where the investigation was narrowed from 400 possible machines to eight based on a comparative study of the photocopy toners.

This paper describes an Isotope dilution GC/MS technique for the analysis of low-parts-per-bllllon concentrations of atrazine, lindane, pentachlorophenoi, and diazinon In water and soil. Known amounts of stable-labeled Isotopes such as atrazlne-d5, llndane-d6, pentachlorophenol-13C e, and dlazlnon-d10 are

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An isotope dilution GC/MS technique for the analysis of low part per billion (ppb) concentrations of dicamba and 2,4-D in water and soil is described. Known amounts of stable-labeled isotopes such as dicamba-d, and 2,4-D-d3 are spiked into each sample prior to extraction. Water samples are extracted with methylene choride at pH 51; soil samples are extracted with acetone-hexane at pH 51. Analysis is performed by high-resolution GC/MS, with the mass spectrometer operated in the selected ion monitoring mode, following derivatization of extracts with pentafluorobenzyl bromide. Accuracy greater than 84% and precision better than 19% were demonstrated with spiked samples. This technique has been used successfully in the analysis of over 300 water and 300 soil samples. Detection limits of 0.1-1.0 ppb for waters and 1-10 ppb for soils were achieved by selected ion monitoring GC/MS.

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