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Appearance
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White to light yellow and faint beige to light beige and faint brown to light brown powder
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pH 8.2-9.8
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Colourless to violet red
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Absorption maxima in 0.1 N NaOH
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565 - 569 nm
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Specific absorptivity A1%/1cm (at λmax)
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Min 1500
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Insoluble matter in ethanol
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Passes test
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Loss on drying (at 135°C)
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Max 0.5%
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Sulphated ash
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Max 0.5%
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