Answer & Procedure
To solve this problem you will need to transform all the concentrations to the equivalence of ppm, which is 1 mg of solute per 1 L of solution.
Calcium: There are 43 μg of calcium in a total volume of 87 mL.
[tex]\frac{43\mu g}{87\text{ mL}}\frac{1\text{ mg}}{1000\text{ }\mu g}\frac{1000\text{ mL}}{1\text{ L}}=0.49\frac{mg}{L}=0.49\text{ ppm}[/tex]Caffeine: There is 0.91 mg of caffeine in a total volume of 105 mL.
[tex]\frac{0.91\text{ mg}}{105\text{ mL}}\frac{1000\text{ mL}}{1\text{ L}}=8.67\frac{mg}{L}=\text{ 8.67 ppm}[/tex]Trace particles: There is 0.47 mg of trace particles in a total volume of 95 dL.
[tex]\frac{0.47\text{ mg}}{95\text{ dL}}\frac{10\text{ dL}}{1\text{ L}}=0.049\frac{mg}{L}=0.049\text{ ppm}[/tex]