Supplier Page from Thermo Fisher Scientific for Niobium foil, 0.127mm (0.005in) thick, 99.97% (metals basis excluding Ta), Ta :<0.06%
2-Ethyl-1,3-hexanediol, 99%, mixture of isomers from Thermo Fisher Scientific
Esculin hydrate, 97% from Thermo Fisher Scientific
Ethyl cyanoacetate, 98+% from Thermo Fisher Scientific
Ethyl oxalyl chloride, 98% from Thermo Fisher Scientific