Final answer:
The scientist can use spectrophotometry to measure the concentration of methyl benzoate in a plant stream.
Step-by-step explanation:
The scientist can use spectrophotometry to measure the concentration of methyl benzoate in a plant stream. Spectrophotometry is a technique that measures the amount of light absorbed or transmitted by a substance at different wavelengths.
To measure the concentration of methyl benzoate, the scientist can prepare a standard solution of known concentration and measure the absorption of light by the solution using a spectrophotometer. The absorption of light is directly proportional to the concentration of the substance being measured, so by comparing the absorption of the standard solution to the absorption of the plant stream, the scientist can determine the concentration of methyl benzoate in the plant stream.