Determining the Iron Content in Vitamins Rachel Warehime & John Siller

Purpose Use two different methods ▫Gravimetric determination ▫Spectrometry determination Various vitamins ▫One A Day (Women’s and Men’s) ▫Prenatal Vitamins ▫General Complete Multivitamin ▫Kids Chewable Tablet ▫Senior Vitamins

Procedure #1 Fired crucibles and weighed until mass was reproduced. Weigh out 0.5 gram sample of each vitamin Dissolve in 3M HCl, add 5 mL 6M HNO3, boil for 2 minutes. Dilute to 200 mL, add 3M ammonia until basic, and boil for 5 minutes. Decant supernatant through ashless filter paper and wash the solid with 1 % NH4NO 3. Allow filter paper to dry for 24 hours. Place filter paper with solid in weighed crucibles and ignite the paper in the 900◦C oven and put the lid on the crucible. Let the crucibles cool for 15 minutes and then weigh them to determine the weight of iron left in the crucibles.

Data Men’s (A&G) ▫A = gG = g Women’s (B&H) ▫B = gH = g Senior (C&I) ▫C = gI = g Kids (D&J) ▫D = gJ = g Prenatal (E&K) ▫E = gK = g General (F&L) ▫F = gL = g

Milligrams of Fe found in vitamins Men’s (A&G) ▫A = 1.61 mg ( g)G = 4.13 mg (0.003 g) Women’s (B&H) ▫B = mg ( g)H = mg ( g) Senior (C&I) ▫C = 27.8 mg (0.02 g)I = 24.1 mg ( g) Kids (D&J) ▫D = 8.8 mg ( g)J = 7.41 mg ( g) Prenatal (E&K) ▫E = dropped lidK = 23.7 mg (0.017 g) General (F&L) ▫F = mg ( g)L = mg ( g)

Comparison Men’s ▫Actual = 0 mgExperimental = 1.61 mg & 4.33 mg Women’s ▫18 mgExperimental = mg & mg Senior ▫8 mgExperimental = 27.8 mg & 24.1 mg Kids ▫15 mgExperimental = 8.8 mg & 7.41 mg Prenata l ▫28 mgExperimental = dropped lid & 23.7 mg General ▫18 mg Experimental = mg & mg

Procedure #2 Place one tablet in a flask with 25 mL of HCl and boil for 15 minutes. Filter the solution once cooled and dilute 5 mL to 100 mL in flask. From this solution, we made 4 more solutions. Pipet 10 mL, 5 mL, 2 mL, and 1 mL into different flasks and dilute them all to 100 mL with distilled water. Measure the absorbance of these solutions at a wavelength of 265 nm

Data Mass of tablets ▫Men’s g ▫Women’s g ▫Senior g ▫Kids g ▫Prenatal g ▫General g

Absorbance Graphs

Discussion First procedure was successful Second procedure was not ▫Human error ▫Better procedure ▫Not using certain chemicals listed  Were not available