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A method is presented for the extraction of the taxane class of natural products, including paclitaxel, from Taxus needles using microwave-assisted extraction (MAE). Various temperatures, times, and organic solvents for the MAE procedure were investigated to optimize the efficiency of the extraction. The effects of biomass to solvent ratio and the water content of the system on taxane recovery were also determined. Under appropriate MAE conditions using 95% ethanol, an extract of the needles was obtained which was equivalent to that produced by a conventional extraction method. The conventional method consisted of an overnight shake of 5 g of needles in 100 mL of methanol at ambient temperature. Thus, with optimized parameter settings, MAE was found to reduce considerably both extraction time and solvent consumption, while maintaining qualitative and quantitative taxane recovery relative to traditional solid/liquid extraction methods. Keywords: Taxanes; paclitaxel; microwave-assisted extraction; Taxus needles

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Manufactured nanomaterials (MNMs) are incorporated as “nanofillers” into consumer products to enhance properties of interest. Multiwalled carbon nanotubes (MWCNTs) are known for their unique properties and have many applications in polymers. However, the release of MWCNTs during the nanoenabled product life cycle is concerning. During the use phase, mechanical stresses can produce fragmented materials containing MNMs. The degree of MNM release, the resulting exposure to these materials, and the potential impacts of their release are active research topics. In this study, we describe methodological improvements to study the abrasion of plastics containing MNMs (nanocomposites) and report on characteristics of abrasion products produced and rates of microplastic production. The abrasion device developed for this work allows for the measurement of power inputs to determine scaled release rates. Abrasion rates for plastics used in 3D printing were found to be 0.27 g/m2/s for the PETG polymer and 0.3 g/m2/s for the 2% MWCNT–PETG nanocomposite. Embedded and protuberant MWCNTs appeared to impact the particle size, shape, hydrophobicity, and surface charge of the microplastics, while the inclusion of MWCNTs had a small effect on microplastic production. Measurements of power input to the abrasion process provided a basis for estimating microplastic production rates for these nanocomposites.