Microcolumn separation and preconcentration of rare earth elements as pyrocatechol violet complexes on anthracene-cetyltrimethyl ammonium bromide adsorbent and their determination in environmental samples by ICP-OES

摘要

A new preconcentration method using a microcolumn packed with anthracene-cetyltrimethyl ammonium bromide as a solid phase adsorbent for the preconcentration of rare earth elements (REEs) prior to their determination by inductively coupled plasma optical emission spectrometry (ICP-OES) has been developed. The method is based on the retention of REEs pyrocatechol violet complexes by anthracenecetyltrimethyl ammonium bromide adsorbent. The metal complexes were eluted from the microcolumn by hydrochloric acid. The main factors affecting the separation/preconcentration of target analytes such as pH, eluent concentration and volume, sample flow rate and volume, pyrocatechol violet concentration, and the interfering ions were studied and the optimal experimental conditions were established. The adsorption capacity of anthracene-cetyltrimethyl ammonium bromide for 16 REEs was 14.4 mg g(-1) Tb - 22.8 mg g(-1) Eu. The detection limits of the method for the 16 REEs were in the range of 11 ng L-1 Yb - 304 ng L-1 Nd with an enrichment factor of 25. The precision values of this method were 1.3% Sc - 9.7% Tb with 7 determinations of 5 ng mL(-1) of target analytes, respectively. The validity of the method was evaluated using a certified reference material of GBWO7401 Soil, and the determined values were in good agreement with the certified values. The developed method was successfully applied to the determination of the rare earth elements in lake water with satisfactory results.