Interferometric observations of chemistry in high-mass star-forming regions

Single dish spectral line surveys of high mass star-forming regions provide spectra with a very high line density, and reveal the presence of many complex molecules. Besides the prototypical Orion BN/KL region, more and more regions get surveyed and we start to get a better idea of the chemical similarities and differences. Yet, single dish studies miss an important aspect of hot cores, which is revealed by higher resolution studies with interferometers: the cores are not chemically homogeneous, but a pronounced chemical substructure exists. As an example of such an interferometric study, we will present one particular set of objects, the UC H-II W3(OH) and its neighboring hot core W3(H2O) (otherwise known as the Turner-Welch object), and discuss their chemical properties.