Often the answer to a tricky question can be found by examining a substance on the most basic of levels. Due to the miniscule scale of atoms and molecules that make up matter all around us, we need to rely on sophisticated analytical methods to tell us what components make up a substance and what properties it possesses. These questions cannot typically be answered by visual observation. Analytical chemistry provides the bridge between what we observe on the macro level and what is actually occuring on the minute atomic and molecular scale.
We use methods that allow for the separation, identification, and quantification of individual chemical species present in complex mixtures. This is useful in a variety of instances, such as determining differences in product formulations, trace chemical anaylsis of fire residues, and identifying impurities that cause accidents or heath effects.
Other techniques used to determine the mechanical properties of plastics and other polymers may provide insight as to why a material failed in use. This testing is often carried out before and after exposure to specific chemicals to assess chemical compatibilities.