Sell DL-Tryptophan

Description

Dl-Tryptophan
Item	Specification
Appearance	White or off white powder
State of Solution	*5.0% Min
Specific Rotation [a]D*0o	*0.5°to *0.5°
Chloride (Cl)	0.*0% Max
Ammonium (NH4)	0.*0% Max
Sulfate (SO4)	0.**0% Max
Iron (Fe)	*0ppm Max
Heavy Metals (Pb)	*0ppm Max
Arsenic (As2O3)	1ppm Max
Loss on Drying	0.2% Max
Residue in Ignition	0.1% Max
PH	5.4 to 6.4
Assay	*8.5% Min

(1) clarity of solution : weigh 0.5 g of dl-tryptophan, and dissolve in *0 ml of 0.5n sodium hydroxide solution. the solution is almost clear, and its color is not darker than that of color standard solution c.

(2) ph : when dl-tryptophan proceed as directed under glass electrode method, ph of an aqueous solution (1�0) should be 5.5~7.0

(3) arsenic : 0.*5 g of dl-tryptophan is dissolved in 3 ml of 1 n hydrochloric acid and 2 ml of water, use as test solution. this test solution proceed as directed under arsenic and it should be appropriate and not more than 4ppm.

(4) heavy metals : proceed as directed under purity (2) in [guar gum], the content should not be more than *0ppm.

(5) chloride : when 0.5 g of dl-tryptophan proceed as directed under chloride, its content should not be more than the amount that corresponds to 0.3 ml of 0.*1 n hydrochloric acid.