A Single Digestion Procedure for Determination of Major, Trace, and Rare Earth Elements in Sediments

The simultaneous determination of major, trace, and rare earth elements in sediments requires the development of specific procedures to prevent interfer- ences. A single digestion method adapted from the EPA method 3051A is proposed for the quantification of 42 elements in sediments by inductively coupled plasma techniques associated with optical emission spectroscopy (ICP-OES) and mass spectrometry (ICP- MS). A combination of different acids and microwave- assisted acid extraction following hot plate extraction was tested. Evaluation of applicability range, linearity, limits of detection and quantification, selectivity, repeat- ability, intermediate precision, and trueness showed the accurate determination of all elements. Selectivity, pre- cision, and trueness values were below the criteria established by the laboratory. The applicability of the proposed method was tested in real sediment samples. For each element, difference between duplicates was lower than the corresponding repeatability limit, with the coefficients of variation ranging between 1.7 and 14%. These results point to the usefulness of this meth- od in multi-element determination of major, minor, trace, and REE in sediment samples, showing its appli- cability in environmental studies related, namely to sediment characterization, monitoring programs, assess- ment of environmental impacts, sediment provenance, and post-depositional mechanisms.This work was developed within the scope of the projects LAQV-REQUIMTE (UIDB/50006/2020), CICECO (UIDB/50011/2020+UIDP/50011/2020), CESAM (UIDB/50017/2020+UIDP/50017/2020), and CIIMAR (UID/Multi/04423/2019), funded national funds through the FCT/ MEC, and co-funded by the FEDER, within the PT2020 Partnership Agreement and COMPETE2020. Authors thank to Euromargins MVSeis Project (01-LEC-EMA24F; PDCTM72003/DIV/40018). Rui Monteiro also acknowledges FCT– Fundação para a Ciência e a Tecnologia, I.P., for his grant (SFRH/BD/108535/2015), A. T. Reis for her grant (SFRH/BPD/ 122112/2016), and Bruno Henriques his Research position funded by national funds (OE), through FCT, in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/ 2017, of July 19.