Abstract
Lanthanum phosphate quantitatively coprecipitated iron(III) ion over the pH range of 2-7 and iron(II) ion at the pH of more than 5, however, the recovery of iron(II) ion decreased with a decrease of the pH below 5. Since the coprecipitation of iron ion could be effectively suppressed at pH 2.8 by the addition of ascorbic acid as a reducing agent and lead(II) ion was also quantitatively coprecipitated with lanthanum phosphate without any influence of ascorbic acid at this pH, lead(II) ion ranging from 1-50 μg could be efficiently separated from 100 mL of the solution containing up to 500 mg of iron ion. The separated lead(II) ion could be readily determined by inductively coupled plasma atomic emission spectrometry. The detection limit (3σ) in this method was 0.47 μg of lead(II) ion. This method was applicable to the determination of lead in iron waste.
