(Solved): 3. A 10.067g sample of cereal is placed in a 250mL Erlenmeyer flask along with 1 -g of sodium as ...

3. A $10.067\mathrm{g}$ sample of cereal is placed in a $250-\mathrm{mL}$ Erlenmeyer flask along with 1 -g of sodium ascorbate, $40-\mathrm{mL}$ of ethanol, and $10-\mathrm{mL}$ of $50\%\mathrm{w}/\mathrm{v}\mathrm{KOH}$. After refluxing for 30 minutes, $60-\mathrm{mL}$ of ethanol is added, and the solution is cooled to room temperature. Vitamin A is extracted using three $100-\mathrm{mL}$ portions of hexane. The combined portions of hexane are evaporated, and the residue containing vitamin $\mathrm{A}$ is transferred to a $5-\mathrm{mL}$ volumetric flask and diluted to volume with methanol. A standard addition is prepared in a similar manner using a $10.093\mathrm{g}$ sample of the cereal and spiking it with $0.0200-\mathrm{mg}$ of vitamin A. Injecting the sample and standard addition into the HPLC gives peak areas of $6.77\times 10^3$ and $1.32\times 10^4$, respectively. Report the vitamin A content of the sample in milligrams per $100\mathrm{g}$ cereal.