Supplier Page from Thermo Fisher Scientific for Calcium oxalate monohydrate, Puratronic:r, 99.9985% (metals basis), (excluding 25ppm max alkali earths)
2-Ethoxyethyl ether, 98+%, extra pure from Thermo Fisher Scientific
4-Ethylresorcinol, 98% from Thermo Fisher Scientific
Ethyl 3-pyridylacetate, 99% from Thermo Fisher Scientific
Ethyl indole-2-carboxylate, 97% from Thermo Fisher Scientific