The phrase "amounts of substances" is correct and usable in written English.
It can be used in scientific or technical contexts when discussing the quantity of different materials or chemicals.
Example: "In the experiment, we measured the amounts of substances required for the reaction to proceed effectively."
Alternatives: "quantities of materials" or "volumes of compounds".
Separation methods, then, can be defined as processes that change the relative amounts of substances in a mixture.
The other concerned a radio-immunoassay technique that can detect trace amounts of substances in the body and that is now used every day throughout the world.
At equilibrium, the two opposing reactions go on at equal rates, or velocities, hence there is no net change in the amounts of substances involved.
Among herbs and other specialty products, melatonin and homeopathic products -- prepared from minuscule amounts of substances as diverse as salt and snake venom -- had the most reports of reactions in 2005.
Industrial alcohol, therefore, is denatured by the addition of small amounts of substances that are carefully chosen to be highly unpleasant in taste and hard to remove but that do not interfere with the intended industrial use.
A simplified form of the same principle evolved as ''paper chromatography," in which small amounts of substances could be separated on filter paper and identified by appropriate colour reactions.
The outputs are the annual amounts of substance released to the different environmental compartments (regional air, regional water, regional soil).
These represent the relationship between the amounts of substance adsorbed on the adsorbent and amount of adsorbate remained in the solution.
Surface enhanced Raman scattering (SERS) spectroscopy is a powerful technique that provides molecular information through greatly enhanced Raman scattering from minute amounts of substance near nanostructured metallic surfaces.
Indeed, hypoxic tissues can accumulate considerable amounts of substance of nitroimidazoles via an oxygen-level dependent reductive mechanism [ 46].
In that study, substantial amounts of substance P have been found, which is a key mediator of inflammatory processes [ 44].
