Validation of microwave acid digestion, diffusive gradients in thin-film preconcentration and inductively coupled plasma optical emission spectrometry methodology for the determination of REEs in natural zeolites
Marin Șenilă, Erika Andrea Levei, Lacrimioara Șenilă, Oana Cadar
Abstract
. A supplementary step of preconcentration/matrix separation based on the passive sampling by diffusive gradients in thin-films (DGT) technique improved the LOQs by about 20 times after three days of passive accumulation, allowing the measurement of the concentrations of all studied REEs in natural zeolite samples. The proposed methodology is a suitable approach for the measurement of REEs at low concentrations in natural zeolite samples by ICP-OES, and it can be extended to other geological samples. The measurement uncertainty was calculated based on the validation data. The proposed method provides reliable results for the measurement of REEs in natural zeolites and was used to measure the specific concentrations of REEs in natural zeolite samples from three Romanian quarries. The REE concentration can be used as a fingerprint for each deposit.