Spectroscopic studies are useful in a range of areas, from remote sensing and radio astronomy to the medical community. Since spectroscopy can provide information used to identify chemicals, new techniques have been developed for high-resolution measurements of chemical absorption frequencies. These high-resolution measurements not only enhance accuracy of the molecule‘s energy level transitions, but also allow for environmental information to be gathered through collisional broadening of the spectral lines. High-resolution measurements, made possible by far-infrared lasers coupled with Schottky diodes, were supplemented with data taken by variable pathlength FTIR measurements in the terahertz region. Chemicals investigated include methanol, nitromethane, water and its isotopes.