Determination of I-129 in environmental solid samples using pyrolysis separation and accelerator mass spectrometry measurement

An optimized pyrolysis method was presented for release of iodine from environmental solid samples with almost quantitative recovery of iodine. The released iodine trapped in alkali solution was separated using a simple and reliable AgI precipitation method, which was directly used for determination of I-129 using accelerator mass spectrometry (AMS). The mechanism of iodine released in pyrolysis was explored. Surface soil samples collected from the Northwest China were successfully analyzed for I-129, showing that I-129 in this area falls to the background level of North Hemisphere