The determination in problem 15-9 was modified to use the standard-addition method. in this case, a 3.925-g tablet was dissolved in sufficient 0.10 m hcl to give 1.000 l. dilution of a 20.00-ml aliquot to 100 ml yielded a solution that gave a reading of 415 at 347.5 nm. a second 20.00-ml aliquot was mixed with 10.0 ml of 50-ppm quinine solution before dilution to 100 ml. the fluorescence intensity of this solution was 503. calculate the percentage of quinine in the tablet.