Chemical analysis of archaeological material goes back to the French chemist Marcelin Berthelot's survey of about 150 Egyptian and Near Eastern artifacts in the late nineteenth century, and continued through Earle Caley's American work from the late 1930s onward, but nobody appears to have fixed a single moment when the practice became a named field rather than a recurring collaboration between two older disciplines. Caley's own retrospective papers describe a history rather than announce a founding.
What would resolve this A dedicated historiographic study of archaeological chemistry's own institutional history, comparable to the histories that exist for archaeometry (dated to the 1958 founding of the Oxford Research Laboratory for Archaeology and the History of Art) or radiocarbon dating (dated to Willard Libby's 1949 paper). No such study of archaeochemistry specifically has been identified; one would need to trace when practitioners first identified as archaeochemists rather than as chemists who occasionally worked on archaeological material.
OpenHistory of chemistry and history of archaeology, tracing when chemical analysis of archaeological material stopped being an occasional collaboration and became a named, self-identified subfield.Earle R. Caley, The Early History of Chemistry in the Service of Archaeology (Caley, Journal of Chemical Education, 1967)