Physical Chemical Characterization of Five Earthy-Musty-Smelling Compounds

Abstract

The occurrence of earthy-musty taste and odors in potable water supplies has been attributed to the presence of several organic compounds at ng/l, including geosmin, 2-methylisoborneol (MIB), 2-isobutyl-3-methoxy pyrazine, 2-isopropyl-3-methoxy pyrazine and 2,4,6-trichloroanisole. Microana-lytical techniques were employed for determining the physical/chemical properties of these compounds, hitherto uncharacterized. The properties determined were melting point, boiling point, refractive index, density, aqueous solubility, octanol/water partition coefficient and Henry's law constant. Since standard micromethods could not be employed for geosmin and MIB because of their scarcity, either these methods were refined or new procedures were developed. The experimental techniques were tested with reference compounds, the properties of which were reported in the literature. Statistical analysis reflected the accuracy and reproducibility of these procedures.