Determination of trace rare earth elements in fruits by microwave digestion coupled with inductively coupled plasma optical emission spectrometry

Abstract

In this work, a novel method was developed for the determination of trace rare earth elements (REEs) in fruit samples by microwave digestion coupled with inductively coupled plasma optical emission spectrometry (ICP-OES) after preconcentration with N, N, N′, N′-tetraoctyl diglycolamide (TODGA). The parameters affecting the extraction and back-extraction behaviors of the target analytes in liquid-liquid extraction (LLE) were studied systematically. Under the optimum conditions, the limits of detection (3σ, n = 7) for the target REEs of interest were in the range of 0.0548 (Tb)–0.541 (La) μg L−1, and the tolerable concentration ratios were reaches 4 orders of magnitude for the common interfering ions. The relative standard deviations (c = 100 μg L−1, n = 7) were from 0.6% (Sm) to 3.3% (La) with the wide linear range spanned three orders of magnitude (R2 > 0.999). The recoveries for the spiked fruit samples were ranged from 92.1% to 104%. The proposed method has the advantages of simple operation, good anti-interference ability, simultaneous determine 16 REEs, which has been successfully applied for analysis of REEs in the 10 locally collected fruit samples, thereby exhibits application potential for the analysis of trace REEs in biological samples with complex matrix.