RNAA used in determination of [sup.129]I in a mixed resin sample

A [k.sub.0]-RNAA procedure was developed to determine [sup.129]I in a mixed resin sample. C[H.sub.4] extraction and [(N[H.sub.4]).sub.2]S[O.sub.3] back-extraction were used to separate [sup.129]I in ashed samples. The [sup.129]I target sample for irradiation in the reactor was prepared by heating the [(N[H.sub.4]).sub.2]S[O.sub.3] back-extraction solution to reduce its volume and then to dry it in a quartz ampoule. No MgO and LiOH were needed during the target sample preparation. After irradiation, the nuclide [sup.130]I was purified by combining hydrated antimony pentoxide column and C[H.sub.4] extraction separations. A k-factor was determined for the reaction of [sup.127]I(n,2n) [sup.126]I and used for iodine chemical yield determination. The apparent [sup.129]I concentrations of five nuclear reaction interferences were calculated. The relative standard deviation of three [sup.129]I determinations was found to be 3.5%. The [sup.129]I content in the analyzed resin was found to be 1.36 x [10.sup.-9] g/g (8.63 x [10.sup.-3] Bq/g) with a relative uncertainty of 9.1 %. The detection limit of [sup.129]I was calculated to be 7.4 x [10.sup.-13] g (4.7 x [10.sup.-6] Bq) in a [k.sub.0]-RNAA of a blank sample. Keywords [sup.129]I * [k.sub.0]-RNAA * [sup.129]I target sample preparation * Iodine chemical yield determination * Nuclear reaction interference