Sample preparation is broadly defined here to include:
Synthesis of engineered nanomaterials (ENMs)
Fabrication of composite materials in which ENMs are embedded in a matrix material; many nanotechnology-enabled products (NEPs) are manufactured from such nanocomposites

• Procedures for the generation of ENM, composite, or NEP samples for subsequent measurements
• Procedures for the generation of ENMs released from NEPs by processes such as mechanical abrasion and weathering

The development of a sample preparation protocol is challenging for a number of reasons. ENMs have large surface-to-volume ratios and, on exposure to various media, may undergo transformations such as agglomeration and adsorption of natural organic matter during sample preparation. Typically, each type of measurement requires that a sample be in a specific physical form; thus, a number of different sample preparation procedures are required for measurements of ENMs, composites, or NEPs by multiple methods. Finally, reproducibility of sample preparation procedures can only be ascertained via measurements of specific ENM properties.