TY - JOUR

T1 - Metal-organic framework application for mercury speciation using solid phase extraction followed by direct thermal release-electrothermal atomization atomic absorption spectrophotometric detection (ETA AAS)

AU - Volynkin, Sergey S.

AU - Demakov, Pavel A.

AU - Shuvaeva, Olga V.

AU - Kovalenko, Konstantin A.

N1 - Publisher Copyright: © 2021 Elsevier B.V.

PY - 2021/9/8

Y1 - 2021/9/8

N2 - Metal-organic frameworks (MOFs) are increasingly used in analytical chemistry for pre-concentration of trace elements followed by their determination using modern analytical techniques. However, there are a limited number of publications concerning the use of MOFs for speciation purposes, while their structural and functional features are perspective for the element species selective extraction and pre-concentration. It is known that mercury refers to the most hazardous elements which species demonstrate different toxicity, migration routes and bioavailability as well. Consequently the development of new approaches for mercury speciation in environments remains an actual objective of analytical chemistry. In present work a new methodology for inorganic and organic mercury speciation in water was proposed. This approach is based on pre-concentration using solid phase extraction (SPE) followed by their determination directly from the solid phase with the application of the thermal release - electrothermal-atomic-absorption technique (TR-ETA-AAS). An original SPE-procedure based on the use of UIO-66 [Zr6O4(OH)4(bdc)6] in two different modes (non-modified and modified with cysteine) as a sorbent was designed. As a result of SPE as well as TR-ETA-AAS optimization the detection limits (LOD) for all listed species at the level of 0.06 μg L-1 have been achieved. It was also shown that the presence of the other elements (K, Na, Ca, Mg at the level of 100 μg L-1, and Mn, Fe, Cr, Al, Zn, Cd, Pb - of 25 μg L-1) does not affect the results obtained. The developed assay demonstrates a high efficiency, low LODs, wide linear range and admissible analysis duration. The reliability of the data obtained was confirmed by the standard addition approach and by a comparison with the results of independent analytical methods.

AB - Metal-organic frameworks (MOFs) are increasingly used in analytical chemistry for pre-concentration of trace elements followed by their determination using modern analytical techniques. However, there are a limited number of publications concerning the use of MOFs for speciation purposes, while their structural and functional features are perspective for the element species selective extraction and pre-concentration. It is known that mercury refers to the most hazardous elements which species demonstrate different toxicity, migration routes and bioavailability as well. Consequently the development of new approaches for mercury speciation in environments remains an actual objective of analytical chemistry. In present work a new methodology for inorganic and organic mercury speciation in water was proposed. This approach is based on pre-concentration using solid phase extraction (SPE) followed by their determination directly from the solid phase with the application of the thermal release - electrothermal-atomic-absorption technique (TR-ETA-AAS). An original SPE-procedure based on the use of UIO-66 [Zr6O4(OH)4(bdc)6] in two different modes (non-modified and modified with cysteine) as a sorbent was designed. As a result of SPE as well as TR-ETA-AAS optimization the detection limits (LOD) for all listed species at the level of 0.06 μg L-1 have been achieved. It was also shown that the presence of the other elements (K, Na, Ca, Mg at the level of 100 μg L-1, and Mn, Fe, Cr, Al, Zn, Cd, Pb - of 25 μg L-1) does not affect the results obtained. The developed assay demonstrates a high efficiency, low LODs, wide linear range and admissible analysis duration. The reliability of the data obtained was confirmed by the standard addition approach and by a comparison with the results of independent analytical methods.

KW - Mercury speciation

KW - Metallorganic framework

KW - Solid phase micro-extraction

KW - Spectrophotometry, Atomic

KW - Reproducibility of Results

KW - Metal-Organic Frameworks

KW - Solid Phase Extraction

KW - Mercury

UR - http://www.scopus.com/inward/record.url?scp=85116171965&partnerID=8YFLogxK

U2 - 10.1016/j.aca.2021.338795

DO - 10.1016/j.aca.2021.338795

M3 - Article

C2 - 34482884

AN - SCOPUS:85116171965

VL - 1177

SP - 338795

JO - Analytica chimica acta

JF - Analytica chimica acta

SN - 0003-2670

M1 - 338795

ER -