These concentrations are considerably higher than those found in EBC, which are in the low nanomole range.
These techniques are considered the reference techniques for the determination of complex mixtures of organic compounds present at nanomole levels in aqueous matrices.
Now you know how many nanomoles you need and you know how much 1 nanomole weighs, and you can calculate the mass of how much you add.
In a table, show how many nanomoles of nitrophenol were produced in each of your enzyme assay tubes.