Flexible metal substrates for long-length high-temperature superconducting (HTS) wires, typically Ni or Ni-alloy foils, include single or multiple buffer layer coatings to provide chemical barriers for the active HTS layer. Chemical issues abound in these multilayer structures, including both intended and unintended bulk reactions, interlayer reactions (corrosion, interlayer compounds), and interlayer diffusion. These effects are a consequence of subjecting multilayer metal/dielectric structures to the rigors of vacuum processing and ex situ conversion reactions. Data are presented that show the applicability of dynamic SIMS (quadrupole, Cs+) in the development of chemically robust structures for HTS applications. (C) 2004 Elsevier B.V. All rights reserved.