| Property | Specification | Test Method | Units |
|---|---|---|---|
| Appearance | White crystalline solid or flakes | Visual | – |
| Assay (as C₄H₂O₅) | Min 99.0% (typical) | Titrimetry | wt% |
| Melting Point | ~102°C | Melting Point Apparatus | °C |
| Sublimation Point | ~200°C | Sublimation Test | °C |
| Water Content | Max 0.5% | Karl Fischer Titration | wt% |
| Insoluble Matter | Max 0.1% | Gravimetry | wt% |
| Color (APHA) | Max 50 | Freezing Point Apparatus | – |
| Acidity (as maleic acid) | Max 0.5% | Titrimetry | wt% |
| Fumaric Acid | Max 0.5% | Gas Chromatography | wt% |
| Chlorides (as Cl) | Max 50 ppm | Ion Chromatography | ppm |
| Sulfates (as SO₄) | Max 100 ppm | Ion Chromatography | ppm |
| Iron (as Fe) | Max 20 ppm | Atomic Absorption Spectroscopy (AAS) | ppm |
| Heavy Metals (as Pb) | Max 5 ppm | Atomic Absorption Spectroscopy (AAS) | ppm |
