The absorption maxima of ephedrine hydrochloride and chlorocresol are 257 nm and 279 nm respectively and the A (1%, 1 cm) values in 0.1M hydrochloric acid solution are: 9.0 and zero for ephedrine hydrochloride at 257 nm and at 279 nm respectively. For chlorocresol it is 20.0 and 105.0 at 257 nm and at 279 nm respectively. Calculate the concentration of ephedrine hydrochloride in a batch of Ephedrine hydrochloride injection, diluted 1 to 25 with water, giving the absorbance in 1 cm cell of 0.424 at 279 nm and 0.972 at 257 nm.