1 | Description | Almost white crystalline powder On exposure to light it gradually darkens. | White or almost white or slightly yellow crystals or crystalline powder On exposure to light it gradually darkens. |
2 | Solubility | Passes | Freely soluble in water; sparingly soluble in ethanol (96%) and in alcohol; insoluble in chloroform, in ether & in benzene. |
3 | Appearance of solution | Passes | Solution should be clear & not more intensely colored than reference solution BY7. |
4 | Identification (By UV spectrophotometry) | Complies | Absorption maximum at 243 nm & specific absorption at absorption maximum : 545 to 585 |
5 | Identification (By IR) | Complies | IR spectra of the sample should be concomitant with IR spectra of the corresponding standard. |
6 | Identification (By pH) | 2.3 | pH of solution : 2.1 to 2.6 |
7 | Identification (By chemical test 1) | Complies | A grey precipitate should form |
8 | Identification (By chemical test 2) | Complies | A 20 mg/mL solution reduces alkaline cupric tartrate solution slowly at room temperature but more readily upon heating |
9 | Specific optical rotation | +20.9° | +20.5° to +21.5° |
10 | Melting point | 188.8°C | About 190°C with decomposition |
11 | Impurity E (Oxalic acid) | Less than 0.2% | 0.2% max. |
12 | Related substances Impurity C (L-sorbosonic acid) | Less than 0.15% | 0.15% max. |
13 | Related substances Impurity D (Methyl L-sorbosonate) | Less than 0.15% | 0.15% max. |
14 | Related substances: unspecified impurity | Less than 0.10% | 0.10% max. |
15 | Related substances: Sum of impurities other than C and D | Less than 0.2% | 0.2% max. |
16 | Copper (Cu) | Less than 5ppm | 5ppm max. |
17 | Iron (Fe) | Less than 2ppm | 2ppm max. |
18 | Sulphated ash / Residue on ignition | 0.06% | 0.1% max. |
19 | Assay | 99.37% | 99.0% to 100.5% |