(Solved): A scientist wishes to measure the concentration of methyl benzoate in a plant stream by gas chroma ...

A scientist wishes to measure the concentration of methyl benzoate in a plant stream by gas chromatography. He prepares a sample of butyl benzoate to use as an internal standard. The results of a preliminary run, which used a solution known to contain \( 1.99 \mathrm{mg} / \mathrm{mL} \) of methyl benzoate (peak A) and \( 2.19 \mathrm{mg} / \mathrm{mL} \) of butyl benzoate (peak B), are shown. The area of peak A is determined to be 335 and the area of peak B is determined to be 376 measured in arbitrary units by the computer. To measure the sample, \( 1.00 \mathrm{~mL} \) of a standard sample of butyl benzoate containing \( 2.39 \mathrm{mg} / \mathrm{mL} \) is mixed with \( 1.00 \mathrm{~mL} \) of the plant stream material. Analysis of the mixture gave a peak area of 491 for peak A and 423 for peak B. What is the concentration of methyl benzoate in the plant stream?