DETERMINATION OF LEAD IN PHOSPHATE ORE AND PHOSPHOGYPSUM

A method is presented for the lead determination in calcium phosphate and -sulphate matrices. Pb is separated from the matrix by solid-liqui d extraction on a Pb-selective column ''SrSpec'' (Eichrom) and subseq uently determined by graphite furnace atomic absorption spectrometry. The yield of the chemical separation is determined by using Pb-210. Th e method is suitable in principle for any material containing more tha n three times the standard deviation in the blank, being 30 mu g kg(-1 ) Pb. Application of the method to phosphogypsum, phosphate ore, phosp horic acid and (certified) reference materials such as soils, sediment s, coal fly ash, citrus leaves and cabbage yielded accurate Pb results .