Supplier Page from Thermo Fisher Scientific for Tungsten foil, 0.1mm (0.004in) thick, 99.95% (metals basis)
Estrone, 99+% from Thermo Fisher Scientific
Ethyl 3-aminobenzoate, methanesulfonic acid salt, 98% from Thermo Fisher Scientific
Ethyl 4,4,4-trifluoroacetoacetate, 97% from Thermo Fisher Scientific
Ethyl acetoacetate, 99%, pure from Thermo Fisher Scientific