Supplier Page from Thermo Fisher Scientific for Niobium foil, 0.127mm (0.005in) thick, 99.97% (metals basis excluding Ta), Ta :<0.06%
2-Ethylhexanoic acid, 99% from Thermo Fisher Scientific
Ethyl acetoacetate, 99%, pure from Thermo Fisher Scientific
Ethyl carbazate, 97% from Thermo Fisher Scientific
Ethyl propiolate, 99% from Thermo Fisher Scientific