Determination of elemental iodine by gas chromatography with electron capture detection

A gas chromatography/electron capture detector (GC/ECD) technique has been developed to determine elemental iodine in toluene and cyclohexane solvents. The retention index based on the alkyl iodide and n-paraffin series was determined. Sufficient resolution was obtained to resolve I2 from alkyl iodides. A detection limit of 39 ng of I2 was obtained. A dissociative electron capture mechanism was proposed for the ECD response to I2. Radiotracer studies established the I2 was transmitted through the column without conversion to an organic iodide. The utility of the developed technique was demonstrated on a AgI in NH4OH mass spectrometry standard solution. An accuracy of 23% and a precision of 12% were demonstrated. 6 references, 8 figures, 2 tables