FAST, SELECTIVE AND SENSITIVE METHODS FOR THE DETERMINATION OF PB-210IN PHOSPHOGYPSUM AND PHOSPHATE ORE

Two methods are presented for a fast, accurate and precise determinati on of Pb-210 in industrial samples with a calcium-phosphate and -sulph ate matrix. One method combines solid-liquid extraction on a ph-select ive column ''SrSpec'' (Eichrom) with gamma-ray spectrometry of Pb-210 ,d can be applied to samples >10 g for a selective Pb-210 determinatio n. The yield is determined gravimetrically. The detection limit is 380 mBq for a 24 h counting period. The other method combines chromatogra phy on SrSpec with liquid scintillation counting of Pb-210 for a sens itive Pb-210 determination and can be applied to samples of up to 1 g. The yield is determined on-line by the UV signal of PbEDTA. The detec tion limit is 70 mBq for a 2 h counting period. Aspects of accuracy, p recision, selectivity, sensitivity and the application of both methods to phosphogypsum and phosphate ores are presented.