| Property | Specification | Test Method |
|---|---|---|
| Assay (as SO₂) | ≥ 60.0% | Titrimetric Analysis |
| Total Purity | ≥ 88.0% | Gravimetry |
| Appearance | White, crystalline powder | |
| pH (10% solution) | 4.0 – 5.5 | Potentiometric |
| Clarity (10% solution) | Clear | |
| Moisture Content | ≤ 0.5% | Karl Fischer Titration |
| Iron (Fe) | ≤ X ppm | Atomic Absorption Spectroscopy (AAS) |
| Arsenic (As) | ≤ X ppm | Inductively Coupled Plasma Mass Spectrometry (ICP-MS) |
