| Popis: |
Two Early Classic period (ca. 250-600 CE) Maya carved, greenstone jade pendants, Specimens A and B, were recovered from the Pacbitun site in Belize in 1987. The specimens were visually similar and may have been cut from a common jade piece. Mass spectrometry was considered as a technique that could possibly be used to explore the similarity of the specimens. However, at that time, neither electrospray ionization nor matrix-assisted laser desorption/ionization (MALDI) had been discovered; furthermore, only elemental analysis had been carried out with jade samples and there were no accounts of polyatomic ions being produced from jade. The discoverer of the greenstone jade pendants, a faculty member in Anthropology at Trent University, sought the assistance of the author of this piece but no immediate progress was accomplished. About 7 years after discovery of the greenstone jade pendants, this author was invited to spend a short sabbatical leave in the laboratory of Dr. Pietro Traldi in Padova, Italy. While this invitation was attractive for several reasons, the principal attraction was Dr. Traldi's new, and mysterious acquisition of MALDI instrumentation. There was, perhaps, a single iota of reason that appeared to suggest unusual assistance of a matrix in liberating polyatomic ions from jade using laser irradiation. This account is of a very interesting sojourn with Dr. Traldi and members of his laboratory which did not lead to any immediate understanding of MALDI; however, the belief was constant for the next 20 years after which some progress was made in the exploration of the structure of jade. |
Plný text