We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Optimization of a pre-concentration method for the analysis of mercury isotopes in low-concentration foliar samples.
- Authors
Ali, Saeed Waqar; Božič, Dominik; Vijayakumaran Nair, Sreekanth; Živković, Igor; Gačnik, Jan; Andron, Teodor-Daniel; Jagodic Hudobivnik, Marta; Kocman, David; Horvat, Milena
- Abstract
Hg isotope analysis in samples from background regions is constrained by the presence of low Hg concentration and therefore requires a pre-concentration method. Existing Hg pre-concentration methods are constrained by long sample processing time and limited sample loading capacity. Using foliar samples as a test case, an optimized Hg pre-concentration method is presented that involves the microwave-assisted digestion of samples for Hg isotope analysis with the addition of a pre-digestion step. Microwave-digested foliar samples and CRMs were transferred to an impinger, reduced with SnCl2, and collected in a 2.25 mL concentrated inverse aqua regia (3:1 HNO3:HCl, v/v). This resulted in an optimal acid concentration in the solution ideal for analysis on MC-ICP-MS. The time for purging with Hg-free N2 was optimized to 30 min and the efficiency of the pre-concentration method was tested using a combination of approaches. Tests performed on pure reagents and matrix of foliar samples spiked with 197Hg radiotracer showed recoveries averaging 99 ± 1.7% and 100 ± 3.0%, respectively. Mercury at concentrations as low as 1.83 ng g−1 was pre-concentrated by digesting aliquots of foliage samples in individual digestion vessels. Recoveries following their pre-concentration averaged 99 ± 6.0%, whereas recoveries of 95 ± 4.7% and 95 ± 2.5% were achieved for NIST SRM 1575a (pine needle) and reagents spiked with NIST SRM 3133, respectively. Analysis using multicollector-ICP-MS showed low fractionation of δ202Hg during sample pre-concentration with no significant mass-independent fractionation. The proposed method is a relatively simple and robust way to prepare Hg samples for Hg isotopic analysis and is suitable even for complex biological matrices.
- Subjects
NATIONAL Institute of Standards &; Technology (U.S.); MERCURY isotopes; ISOTOPIC analysis; COMPLEX matrices; PINE needles; SAMPLING (Process)
- Publication
Analytical & Bioanalytical Chemistry, 2024, Vol 416, Issue 5, p1239
- ISSN
1618-2642
- Publication type
Article
- DOI
10.1007/s00216-023-05116-5