L-Tryptophan

AJI92

USP40

EP6.0

Description

White to yellowish white crystals or crystalline powder

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White or almost white,crystalline or amorphous powder

Identification

Conform

Conform

Conform

Solubility

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Sparingly soluble in water, slightly soluble in ethanol(96 percent). It dissolves in dilute solutions of mineral acids and alkali hydroxides.

Appearance of solution

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The solution is clear and not more intensively coloured than reference solution BY6

Assay

98.5%~100.5%

98.5%~101.5%

98.5%~101.0%

pH

5.4～6.4

5.5~7.0

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Transmittance

≥95.0%

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Loss on drying

≤0.20%

≤0.3%

≤0.5%

Residue on ignition

≤0.10%

≤0.1%

≤0.1%

Chloride

≤0.020%

≤0.05%

≤200ppm

Heavy Metals

≤10ppm

≤15ppm

≤10ppm

Iron

≤20ppm

≤30ppm

≤20ppm

Sulfate

≤0.020%

≤0.03%

≤300ppm

Ninhydrin-positive substances  (TLC)

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Conform

Arsenic

≤1ppm

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Ammonium

≤0.02%

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≤200ppm

Other amino acids

Meet the requirements

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Pyrongen

Conform

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Specific Rotation

-30.0° ～ -32.5°

-29.4°~ -32.8°

-30.0°～-33.0°

Organic impurities

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Conforms

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