Certified reference material IAEA-418: 129I in Mediterranean Sea water

A certified reference material designed for the determination of I-129 in seawater, IAEA-418 (Mediterranean Sea water) is described and the results of certification are presented. The median of I-129 concentration with 95% confidence interval was chosen as the most reliable estimates of the true value. The median, given as the certified value, is 2.28 x 10(8) atom L-1 (95% confidence interval is (2.16-2.73) 10(8) atom L-1), or 3.19 x 10(-7) Bq L-1 (95% confidence interval is (3.02-3.82) x 10(-7) Bq L-1). The material is intended to be used for standardization procedures applied in accelerator mass spectrometric laboratories. It is available in 1 L units and may be ordered via IAEA web side (www.iaea.org).