Phytic acid functionalized magnetic adsorbents for facile enrichment of trace rare earth elements in environmental water, digested atmospheric particulates and the extracts followed by inductively coupled plasma mass spectrometry detection.

Phytic acid (PA) functionalized magnetic adsorbents was synthesized through simple process. The functionalized sorbents are featured with core-shell structure, good magnetism, chemical stability, selectivity, and fast adsorption/desorption dynamics for the preconcentration of trace rare earth elements (REEs). With the aid of inductively coupled plasma mass spectrometry detection, the prepared FeO@SiO@PA sorbents were employed for the separation and enrichment of 15 REEs from environmental water and atmospheric particulates with different sizes. Under the optimal conditions, the method presented an enrichment factor of 300-fold and low detection limits (0.002-1.1 ng/L) for 15 REEs, with the relative standard deviations of 1.4-4.4%. Environmental water samples were analyzed by the proposed method, and 15 REEs of 0.08-5.80 ng/L were found in local rainwater and river water. The REEs concentration in locally collected fine particulate matter was 0.01-0.93 ng/m, 0.03-1.70 ng/m and 0.03-2.47 ng/m of REEs were found in inhalable particulate matter and total suspended particulate samples, respectively. The bioaccessibility of REEs in PM was evaluated by using Gamble's solution extraction, which was calculated to be 0.73-5.46%.