A Simple Gas Chromatographic Method for the Study of Organic Solvents: Moisture Analysis, Hygroscopicity, and Evaporation

This paper presents the baseline separation of eight common laboratory organic solvents by GC with TCD and simple isothermal conditions. The influence of column temperature on the chromatographic parameters, capacity factor (k), and resolution (R), was studied. Rapid analysis of moisture in organic solvents was demonstrated. A linear detection response of 100 ppm to 30% (v/v) was shown for water in ethanol. Solvent samples placed in open beakers absorbed water at varying rates. The relative rate of hygroscopicity was ethanol, 2-propanol, acetonitrile ethyl acetate, acetone > methanol > chloroform. Solvent samples, stored in stoppered volumetric flasks or septum-capped vials and periodically sampled, gave no significant moisture absorption. A mixture of organic solvents in a slowly stirred open beaker indicated differences in atmospheric evaporation. The relative rate of evaporation was ether » acetone, chloroform, acetonitrile > methanol, ethyl acetate > ethanol, 1-propanol » water.