BHT-二丁基羟基甲苯

FCC V Monographs Biotin 49 and record the areas as directed under Procedure to ensure that the relative standard deviation does not exceed 2 0 for the 3 tert butyl 4 hydroxyanisole isomer and 6 0 for the 2 tert butyl 4 hydroxyanisole isomer the resolution between the isomers is not less than 1 3 and the tailing factor does not exceed 2 0 Procedure Separately inject suitable portions about 5 L of the Standard Preparation and the Assay Preparation into the gas chromatograph and record the chromatograms Measure the areas under the peaks for each isomer and the Internal Standard in each chromatogram and calculate the quantity I in milligrams of each isomer in the sample taken by the equation I 10 CS RU RS in which CS is the concentration in milligrams per milliliter of the isomer in the Standard Preparation RU is the ratio of the area of the isomer to that of the Internal Standard in the chromatogram from the Assay Preparation and RS is the ratio of the area of the isomer to that of the Internal Standard in the chromatogram from the Standard Preparation Calculate the weight in milligrams of C11H16O2 in the sample taken by adding the quantities of the two isomers Residue on Ignition Determine as directed in Method I under Residue on Ignition Appendix IIC igniting a 10 g sample Packaging and Storage Store in well closed containers BHT Butylated Hydroxytoluene 2 6 Di tert butyl p cresol OH CH3 3C C CH3 3 CH3 C15H24O Formula wt 220 35 INS 321 CAS 128 37 0 DESCRIPTION BHT occurs as a white crystalline solid It is freely soluble in alcohol and insoluble in water and in propylene glycol Function Antioxidant REQUIREMENTS Identification Dissolve 200 mg of 3 3 dimethoxybenzidine dihydrochloride in a mixture of 40 mL of methanol and 60 mL of 1 N hydrochloric acid Add 5 mL of the resulting dianisidine solution to 10 mL of water and 2 mL of a 3 100 solution of sodium nitrite Add this solution to 10 mL of a 1 100 000 solution of sample methanol An orange red color appears within 3 min Add 5 mL of chloroform and shake The chloroform layer exhibits a purple or magenta color that fades when exposed to light Assay Not less than 99 0 of C15H24O Residue on Ignition Not more than 0 002 TESTS Assay The solidification point see Solidification Point Ap pendix IIB of a sample is not lower than 69 2 indicating a purity of not less than 99 0 of C15H24O Residue on Ignition Transfer about 50 g of sample accu rately weighed into a tared crucible ignite until thoroughly charred and cool Moisten the ash with 1 mL of sulfuric acid and complete the ignition by heating for 15 min periods at 800 25 to constant weight Packaging and Storage Store in well closed containers Biotin cis Hexahydro 2 oxo 1H thieno 3 4 imidazole 4 valeric Acid d Biotin O C HNNH HC CH CH CH2 4COOH S H2C C10H16N2O3S Formula wt 244 31 CAS 58 85 5 DESCRIPTION Biotin occurs as a practically white crystalline powder It is stable to air and heat One gram dissolves in about 5000 mL of water at 25 and in about 1300 mL of alcohol it is more soluble in hot water and in dilute alkali and it is insoluble in other common organic solvent