Question

You wish to measure the concentration of methyl benzoate in a plant stream by gas chromatography. You prepare a sample of butyl benzoate to use as an internal standard. A preliminary run, shown at the right involved a solution containing 1.55 mg/mL of methyl benzoate and 1.71 mg/mL of butyl benzoate. The area of peak methyl benzoate was determined to be 315 and of butyl benzoate to be 378 (measured in arbitrary units by the computer). To measure the sample, 1.00 mL of a standard sample of butyl benzoate containing 2.43 mg/mL was mixed with 1.00 mL of the plant stream material, and analysis of the mixture gave a peak area of 449 for methyl benzoate and 393 for butyl benzoate. What is the concentration of the methyl benzoate in the plant stream?

Answer 1