| Melting Point | ~122°C (lit., decomposes) |
| Color | White to Yellow |
| Assay Percent Range | 99+% |
| Linear Formula | H5IO6 |
| Formula Weight | 227.94 |
| Physical Form | Crystals/Crystalline Powder |
| Chemical Name or Material | Periodic acid |
| SMILES String | OI(=O)(O)(O)(O)O |
| Identification | Positive for periodate |
| Merck Index | 15, 7286 |
| Sulfated Ash | 0.05% max |
| Additional Information | 1.0% max. Iodic Acid |
| Fieser | 01,815; 02,313; 03,220; 04,374; 05,508; 10,304; 13,238; 16,272 |
| Iron (Fe) | 50ppm max. |
| Sulfate | 200ppm max. |
| Nitrate | 100ppm max. |
| Bromide | 200ppm max. (Bromide, Bromate (as Cl)) |
| Chloride and Chlorate | 200ppm max. (as Cl) |
| Insoluble in Water | 0.01% max. |
| Iodide | 10ppm max. |
| CAS Number | 10450-60-9 |
| EC Number | 233-937-0 |
| MDL Number | MFCD00011344 |
| PubChem CID | 25289 |
| WGK Germany | 3 |
| Iron/Sulfate/Nitrate/Bromide/Chloride limits | all specified, ppm-level |
Periodic Acid Solution is the aqueous form of periodic acid (H5IO6), a hypervalent iodine oxoacid and one of the strongest oxidizing/diol-cleaving agents used in labs. Iodine sits at +7 oxidation state surrounded by five hydroxyls and one oxo group, giving it unusually strong, controllable oxidizing power.
Its signature use is the Malaprade reaction, cleaving vicinal diols into two carbonyls — core to organic synthesis, natural-product chemistry, and carbohydrate analysis. Also strips acetal-type protecting groups and opens epoxides. Dilute solution is the active oxidant in PAS staining for histology/pathology, and it’s used in oxidimetric titration.
