Abstract
This study examines the matrix effect over the trueness for determining total mercury (THg) using CV-AFS. We demonstrate that matrix interferences in soils and sediment samples cannot be eliminated by acid digestion and establish the use of sulfhydryl cotton fiber (SCF), a malleable, cheap and easy to synthesize fiber, as a mandatory solution capable to overcome this bias. Using the classic CV-AFS approach, an overestimation bias for THg recovery values of >140% in a certified reference material was reported. Interference metals test was conducted, thus discarding any influence of metals in the overestimation bias. Therefore, a clean-up step using SCF was proposed, and tests with synthesized fiber did not present a dispersion of >0.08 ng L-1. Moreover, validation was performed by analyzing three certified reference material and yielding mean recovery percentages of 100% ± 1%. A validated methodology was applied to ten environmental soil samples; THg values obtained varied from 129 to 384 ng g-1. Finally, a comparison between sample results obtained and reference method did not show any significant differences (p > 0.05), thus highlighting the efficacy of SCF-CV-AFS for THg quantification in environmental solid samples.
Original language | English |
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Pages (from-to) | 3756-3762 |
Number of pages | 7 |
Journal | Analytical Methods |
Volume | 12 |
Issue number | 29 |
DOIs | |
State | Published - 7 Aug 2020 |