Preconcentration and preseparation procedure for platinum determination attrace levels by neutron activation analysis

A procedure that simultaneously allows. both preconcentration and presepara tion of platinum for its determination by neutron activation analysis at tr ace levels (< 0.1 mug(.)g(-1)) in environmental related matrixes is develop ed. The method is mainly based on a two-step chemical procedure: (i) a prei rradiation concentration/separation based on a column chromatography separa tion where the platinum is previously retained and subsequently separated f rom Au, Ca, Na, Br, and P; (ii) a postirradiation separation/purification o f the Au-199 at 158.4 keV used for the platinum determination via [Pt-198 ( n, gamma) --> Pt-199 beta (-)) --> Au-199] The method eliminates the follow ing radionuclides with the y lines in the region of 158 keV: (SC)-S-47 (dau ghter of Ca) at 159.3 keV; Au-199 (produced by double neutron capture onto the natural Au-197) at 158.4 keV; (123m) Te at 158.8 keV. In addition, the background activity deriving from Na-24, P-32, and Br-82 is drastically red uced. The method ras tested by the analysis of certified rock material and then applied for platinum determination in airborne particulate matter.