Coprecipitation of heavy metals with erbium hydroxide for their flame atomic absorption spectrometric determinations in environmental samples.

Trace amounts of copper, manganese, cobalt, chromium, iron and lead were quantitatively coprecipitated with erbium hydroxide on 0.05M NaOH medium. The coprecipitant could be easily dissolved with 1M nitric acid. The presence of up to 15g/l of erbium ions did not interfere with the atomic absorption spectrometric determination of analyte ions. The recovery values for analyte ions were higher than 95%. The concentration factor was 25-fold. Coprecipitation parameters including reagent amounts and matrix effects are discussed. The relative standard deviations of the determinations were below 9%. The time required for the coprecipitation was about 30min. The proposed method was successfully applied for the determination of trace amounts of analyte ions in urine, soil and sediment, natural water samples.