Supplier Page from Thermo Fisher Scientific for Niobium powder, -325 mesh, Puratronic:r, 99.99% (metals basis excluding Ta), Ta :<500ppm
2-Ethoxyethyl ether, 98+%, extra pure from Thermo Fisher Scientific
Ethyl 2-oxocyclohexanecarboxylate, 95% from Thermo Fisher Scientific
Ethyl butyrylacetate, 98% from Thermo Fisher Scientific
Fluorescein, pure from Thermo Fisher Scientific