A: Evaporate under a stream of nitrogen to dryness 1 mL of the filtrate obtained in Identification test B, and dissolve the residue in 50 mL of alcohol: the UV absorption spectrum of the solution exhibits maxima and minima at the same wavelengths as that of a similar preparation of USP Ergocalciferol RS, concomitantly measured.

B: Triturate a quantity of powdered Tablets, equivalent to about 5 mg of ergocalciferol, with 10 mL of chloroform, and filter into a small flask: the filtrate so obtained responds to Identification test C under Ergocalciferol.