Stability and darkening[edit]
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2025-08-14 16:05
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This precipitate is not suitable for a pigment until it is filtered, dried, crushed, heated to a high temperature and quenched in cold water. The second heating in a muffle furnace at 725 °C produces crystals of the right optical size.
To be added to food, this additive must achieve 99% purity. However, this leaves room for small amounts of potential contaminants like lead, arsenic, or mercury (1Trusted Source).