and aldehyde by mixed addenda Heteropolyacids have long been used in analysis and histology and are a component of many reagents e.g. the Folin-Ciocalteu reagent, folins phenol reagent used in the Lowry protein assay and EPTA, ethanolic phosphotungstic acid. See also Phosphomolybdic acid Phosphotungstic acid Silicotungstic acid Citations References Acid catalysts