Volume of unknown working solution added to each standard addition flask (Vx), ml: J. 000) mL Mass of tablet or capsule (9): 0.48)5 Mass of powder (9): 0.4172) Riboflavin working standard solution (Cs), ppm: 0. 040) Solution ID# Unknown Riboflavin (vol. working std. Working Fluorescence Corrected Fluor. concentration in solution added, ml) Solution Intensity Intensity standard addition Added (ml) flask (ppm) Oml 9.0 0. 155) 0.1394 0 0.5 mL 8.5 0,2039 0.1883 0.002228 1.0 mL 8.0 0. 2468 0.2312 0.004455 1.5 mL 7.5 0.2777 0.2621 0. 006683 2.0 ml 7.0 0. 2990 0.2834 0.00891 2.5 ml 6.5 0.3444 0.3288 0.01114 3.0 ml 6.0 0. 3804 0. 3648 0.013 366 Blank 0.0156 Data Analysis (Excel) Correlation = 0.99559 Slope (4 sig. fig., SF = sig. fig.) | 0.07210 Y-intercept (4 SF) 0.1643 Standard error in y (oY) (3 SF) Number of solutions containing unknown (n) (1 SF) Sum of squares of deviation E(X; - X)2 (5 SF) Mean of y-values (Y) (5 SF) Unknown's riboflavin concentration in standard addition solutions (ppm) Uncertainty or Std. Dev. of riboflavin in standard addition solutions (ppm) Riboflavin in the unknown powder solution (mg) Uncertainty or Std. Dev. of riboflavin in the powder solution (mg) Riboflavin in the unknown tablet (mg) Uncertainty or Std. Dev. of riboflavin in the tablet (mg) Confidence interval based on the uncertainty value (mg)