Radioanalytical Determination of Biogenic Volatile Iodine Emitted from Aqueous Environmental Samples

A reliable method using ¹²⁵I tracer for direct determination of volatile iodine formed in aqueous environmental samples was established. Soil solution, seawater and bacterial cell suspension were selected as model samples, and incubated with ¹²⁵I^–. Volatile inorganic and organic iodine species produced during incubation were collected in silver wool and activated charcoal traps, separately the efficiency of the traps, the storage conditions of ¹²⁵I^– stock solution and the procedures to expel the dissolved volatile iodine from the sample solutions were examined. Formation of biological volatile iodine was observed in all samples, and the dominant iodine species was found to be organic iodine. The advantages of this method are its simplicity, low cost and low detection limit.