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Colorimetric test results.
| Methods | Positive/Negative | Colour observed | |
|---|---|---|---|
| Ferric test | + | Greenish-brown |
|
| Shinoda's test | + | Brown |
|
| Acid butanol test | + | Crimson |
|
| Nitrous acid test | − | Brownish-yellow |
|
| Potassium iodate test | − | Brown |
|
+ positive test, − negative test.
