Beta Carotene
;)
b,b-Carotene.
all-trans-b-Carotene.
(all-E)-1,1¢-(3,7,12,16-Tetramethyl-1,3,5,7,9,11,13,15,17-octadecanonaene-1,18-diyl)bis[2,6,6-trimethylcyclohexene] [7235-40-7].
»Beta Carotene contains not less than 96.0percent and not more than 101.0percent of C40H56.
Packaging and storage—
Preserve in tight,light-resistant containers.
Identification—
A:
Determine the absorbances of Assay preparation Bat 455nm and at 483nm:the ratio of the absorbance at 455nm to that at 483nm is between 1.14and 1.18.
B:
Determine the absorbance of Assay preparation Bat 455nm and that of Assay preparation Aat 340nm:the ratio of the absorbance at 455nm to that at 340nm is not less than 1.5.
Loss on drying á731ñ—
Dry it in vacuum over phosphorus pentoxide at 40
for 4hours:it loses not more than 0.2%of its weight.
for 4hours:it loses not more than 0.2%of its weight.
Residue on ignition á281ñ:
not more than 0.2%,2g of specimen being used.
Heavy metals,Method IIá231ñ:
0.001%.
Organic volatile impurities,Method IVá467ñ:
meets the requirements.
Assay—
[NOTE—Perform this procedure in subdued light,using low-actinic glassware.]
Assay preparation A—
Transfer about 50mg of Beta Carotene,accurately weighed,to a 100-mLvolumetric flask,dissolve in 10mLof acid-free chloroform,dilute with cyclohexane to volume,and mix.Pipet 5mLof this solution into a 100-mLvolumetric flask,dilute with cyclohexane to volume,and mix.
Assay preparation B—
Pipet 5mLof Assay preparation Ainto a 50-mLvolumetric flask,dilute with cyclohexane to volume,and mix.
Procedure—
Determine the absorbance of Assay preparation B,at the wavelength of maximum absorbance at about 455nm,with a suitable spectrophotometer,using cyclohexane as the blank.Calculate the quantity,in mg,of C40H56in the portion of Beta Carotene taken by the formula:
20,000AX/250,
in which AXis the absorbance of Assay preparation B;and 250is the absorptivity of pure beta carotene.
Auxiliary Information—
Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist
Expert Committee:(DSN)Dietary Supplements:Non-Botanicals
USP28–NF23Page 240
Phone Number:1-301-816-8389