PRELIMINARY REFLECTIVE SPECTROSCOPY RESULTS FOR RAPID IDENTIFICATION OF MINERAL-BASED MAKEUP PRODUCTS AND ASSOCIATED PERSONAL CARE PRODUCTS IN THE CONTEXT OF FORENSIC AND HEALTH INVESTIGATIONS

Reflective spectra of a wide variety of mineral-based materials such a make-up, over the counter pharmaceuticals, and a variety of personal care products, amongst other materials, were investigated to determine the nature of variability of these materials in the context of trace evidence for forensic investigations of violence against women and also prevention of exposure to toxic substances. Several personal care products, pharmaceuticals and other materials are distinct from geologic background, wood and other items and thus could likely be identified by reflective spectroscopy. Selected minerals that could potentially be used in make up or in consumer products such as cavansite and sepiolite were examined and within sample variation was found to be very distinctive owing either to water content or chromophore content. For personal care products with high water content identification is more problematic because water features greatly diminish smaller features in the NIR/SWIR. Spectra were compared to a set of well characterized geologic materials as well as spectra from the USGS spectral library. This suggests that many mineral-based makeup products and associated personal care products are distinct from geologic and other materials and thus reflective spectroscopy may be a useful in the context of hand held instruments investigations or expected upcoming hyperspectral camera investigations of crime scenes. Clay-rich and tan makeup however are expected to be problematic on certain soils and certain counter top materials. Extensive combination studies may be needed for complex crime scene environments where geologic materials such as a countertop with several mineral products and materials of ambiguous distributions occur, such as white powders. Detection of some minerals that may cause health concerns in makeup, such as vanadinite, and crocoite should also be possible. Long term efforts to expand on the current investigation should include (1) extensive combination experiments of makeup, personal care products and legal and illegal pharmaceuticals, (2) wet and dry experiments as well as age experiments and (3) experiments to detect harmful pigments such as orpiment, realgar, and galena.