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Appearance
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Silky white crystals, white glistering needles or a white crystalline powder
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Assay (Potentiometric)
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98.5% -101.5% (on died basis)
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Solubility
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Sparingly soluble in water, freely soluble in boiling water, slightly soluble in ethanol (96 per cent). It dissolves in concentrated solutions of alkali benzoates or salicylates.
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Identification
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-
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Identification 'A' & 'B'
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The spectrum of the sample should be concordant with spectrum of caffeine CRS or with the reference spectrum of caffeine
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Identification 'A'
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Melting point - 235 - 237°C
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Identification 'C'
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The precipitate should dissolve
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Identification 'D'
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An intense blue color should develops
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Identification 'E'
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LOD - NMT 0.5%
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Identification 'F'
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It give the reaction of xanthines
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Appearance of solution
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Solution S should be clear and colorless
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Insoluble matter in water
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Max 0.005%
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Acidity
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NMT 0.2 ml of 0.01M NaOH should be required to change the color of indicator to blue
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Related substance (by HPLC)
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-
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Unspecified impurities
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NMT 0.1%
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Total impurities
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NMT 0.1%
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Sulphates
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Max 0.05%
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Sulphated ash
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Max 0.1%
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Copper (Cu)
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Max 0.0002%
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Iron (Fe)
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Max 0.0002%
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Lead (Pb)
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Max 0.0002%
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Zinc (Zn)
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Max 0.0002%
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