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Appearance
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Black-Brown to Orange-Rust Powder
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Dye content
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Min 90%
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Absorption maxima (0.1 mol/L in NaOH) λmax1
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587 - 591 nm
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Extinction coefficient at λmax1
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Min 47000
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Absorption maxima (0.1 mol/L in NaOH) λmax2
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375 - 381 nm
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Extinction coefficient at λmax2
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Min 7000
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pH transition range (pH 5.2 - 6.8)
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Yellow - violet
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