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Extraction and pre-concentration of platinum and palladium from microwave-digested road dust via ion exchanging mesoporous silica microparticles prior to their quantification by quadrupole ICP-MS.

Nischkauer W, Neouze MA, Vanhaecke F, Limbeck A - Mikrochim Acta (2015)

Bottom Line: Pt and Pd concentrations in samples collected in summer and in winter were compared, with concentrations ranging from 205 to 1445 ng g(-1) for Pt and from 201 to 1230 ng g(-1) for Pd.Graphical AbstractMesoporous silica microparticles (μPs) functionalized with quarternary amino groups were used for isolating platinum and palladium from aqueous road dust digests.The μPs were suspended directly in the aqueous digests, and the analyte-loaded μPs were analyzed using "dispersed particle extraction".

View Article: PubMed Central - PubMed

Affiliation: Institute of Chemical Technologies and Analytics, TU Wien, Getreidemarkt 9/164-IAC, 1060 Vienna, Austria ; Department of Analytical Chemistry, Ghent University, Krijgslaan 281 - S12, 9000 Ghent, Belgium.

ABSTRACT

We report on the use of mesoporous silica microparticles (μPs) functionalized with quarternary amino groups for the isolation of platinum and palladium tetrachloro complexes from aqueous road dust digests. The μPs have a size ranging from 450 to 850 nm and are suspended directly in the aqueous digests, upon which the anionic Pt and Pd complexes are retained on the cationic surface. Subsequently, the μPs are separated by centrifugation. Elements that cause spectral interferences in ICP-MS determination of Pt and Pd can be quantitatively removed by adding fresh 0.240 mol L(-1) HCl to the μPs and by repeating the centrifugation step. The analyte-loaded μPs are then dissolved in 0.1 mL of 2 mol L(-1) HF, diluted to 2 mL, and the solutions thus obtained are analyzed by quadrupole ICP-MS. This method avoids analyte elution from the sorbent. This "dispersed particle extraction" approach yielded a run-to-run relative standard deviation ≤ 5 % for Pt and ≤ 4 % for Pd (at 0.1 ng mL(-1), n = 4 road dust digests). Method detection limits (expressed as concentrations in the dust samples) are 2 and 1 ng g(-1) for Pt and Pd, respectively. The method was validated by analysis of a reference material (BCR CRM 723) and applied to the analysis of road dust samples collected in downtown Vienna. Pt and Pd concentrations in samples collected in summer and in winter were compared, with concentrations ranging from 205 to 1445 ng g(-1) for Pt and from 201 to 1230 ng g(-1) for Pd. Graphical AbstractMesoporous silica microparticles (μPs) functionalized with quarternary amino groups were used for isolating platinum and palladium from aqueous road dust digests. The μPs were suspended directly in the aqueous digests, and the analyte-loaded μPs were analyzed using "dispersed particle extraction".

No MeSH data available.


Three successive washing steps result in an effective removal of potentially interfering elements (concentrations at the beginning: 10,000 ng mL−1 for Cu, Zn, Sr, 1000 ng mL−1 for Y, Zr, and 100 ng mL−1 for Cd, Hf, Mo, error bars represent the standard deviation of n = 3 replicates)
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Fig3: Three successive washing steps result in an effective removal of potentially interfering elements (concentrations at the beginning: 10,000 ng mL−1 for Cu, Zn, Sr, 1000 ng mL−1 for Y, Zr, and 100 ng mL−1 for Cd, Hf, Mo, error bars represent the standard deviation of n = 3 replicates)

Mentions: As discussed in the introduction, the removal of spectral interferences is a very important prerequisite for obtaining correct quantitative results. In the road dust CRM (BCR 723), many parent nuclides can be found which potentially cause such spectral interferences (see [14] for an extensive list). Therefore, the effectiveness of removing Cu, Zn, Sr, Cd, Hf, Mo, Y, and Zr from the samples when applying the proposed DPE-method was investigated in more detail. To this end, solutions containing those elements in concentrations expected after digesting BCR 723 road dust were prepared from single-element standards (concentrations ranging from 10,000 to 100 ng mL−1, depending on the element). To simulate the digestion, the solutions were mixed with aqua regia and HF and evaporated repeatedly to near-dryness as described above (see section “sample collection and digestion”). Finally, the samples were taken up in 0.240 mol L−1 HCl and the proposed DPE sample pre-treatment process was carried out three times. The supernatants resulting from each of the three pre-treatment steps were analyzed for their respective element concentrations. As can be seen in Fig. 3, the concentrations of all elements decrease with every washing step, namely to 2.3–7.5 % of the initial concentration after the first washing step (signals obtained from the first supernatant correspond to the digest without any pre-treatment and are normalized to 100 %), to 0.01–0.2 % after the second washing step, and to levels not significantly different from the blank after the third washing step. Therefore, three washing steps were used in all further experiments.Fig. 3


Extraction and pre-concentration of platinum and palladium from microwave-digested road dust via ion exchanging mesoporous silica microparticles prior to their quantification by quadrupole ICP-MS.

Nischkauer W, Neouze MA, Vanhaecke F, Limbeck A - Mikrochim Acta (2015)

Three successive washing steps result in an effective removal of potentially interfering elements (concentrations at the beginning: 10,000 ng mL−1 for Cu, Zn, Sr, 1000 ng mL−1 for Y, Zr, and 100 ng mL−1 for Cd, Hf, Mo, error bars represent the standard deviation of n = 3 replicates)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4608980&req=5

Fig3: Three successive washing steps result in an effective removal of potentially interfering elements (concentrations at the beginning: 10,000 ng mL−1 for Cu, Zn, Sr, 1000 ng mL−1 for Y, Zr, and 100 ng mL−1 for Cd, Hf, Mo, error bars represent the standard deviation of n = 3 replicates)
Mentions: As discussed in the introduction, the removal of spectral interferences is a very important prerequisite for obtaining correct quantitative results. In the road dust CRM (BCR 723), many parent nuclides can be found which potentially cause such spectral interferences (see [14] for an extensive list). Therefore, the effectiveness of removing Cu, Zn, Sr, Cd, Hf, Mo, Y, and Zr from the samples when applying the proposed DPE-method was investigated in more detail. To this end, solutions containing those elements in concentrations expected after digesting BCR 723 road dust were prepared from single-element standards (concentrations ranging from 10,000 to 100 ng mL−1, depending on the element). To simulate the digestion, the solutions were mixed with aqua regia and HF and evaporated repeatedly to near-dryness as described above (see section “sample collection and digestion”). Finally, the samples were taken up in 0.240 mol L−1 HCl and the proposed DPE sample pre-treatment process was carried out three times. The supernatants resulting from each of the three pre-treatment steps were analyzed for their respective element concentrations. As can be seen in Fig. 3, the concentrations of all elements decrease with every washing step, namely to 2.3–7.5 % of the initial concentration after the first washing step (signals obtained from the first supernatant correspond to the digest without any pre-treatment and are normalized to 100 %), to 0.01–0.2 % after the second washing step, and to levels not significantly different from the blank after the third washing step. Therefore, three washing steps were used in all further experiments.Fig. 3

Bottom Line: Pt and Pd concentrations in samples collected in summer and in winter were compared, with concentrations ranging from 205 to 1445 ng g(-1) for Pt and from 201 to 1230 ng g(-1) for Pd.Graphical AbstractMesoporous silica microparticles (μPs) functionalized with quarternary amino groups were used for isolating platinum and palladium from aqueous road dust digests.The μPs were suspended directly in the aqueous digests, and the analyte-loaded μPs were analyzed using "dispersed particle extraction".

View Article: PubMed Central - PubMed

Affiliation: Institute of Chemical Technologies and Analytics, TU Wien, Getreidemarkt 9/164-IAC, 1060 Vienna, Austria ; Department of Analytical Chemistry, Ghent University, Krijgslaan 281 - S12, 9000 Ghent, Belgium.

ABSTRACT

We report on the use of mesoporous silica microparticles (μPs) functionalized with quarternary amino groups for the isolation of platinum and palladium tetrachloro complexes from aqueous road dust digests. The μPs have a size ranging from 450 to 850 nm and are suspended directly in the aqueous digests, upon which the anionic Pt and Pd complexes are retained on the cationic surface. Subsequently, the μPs are separated by centrifugation. Elements that cause spectral interferences in ICP-MS determination of Pt and Pd can be quantitatively removed by adding fresh 0.240 mol L(-1) HCl to the μPs and by repeating the centrifugation step. The analyte-loaded μPs are then dissolved in 0.1 mL of 2 mol L(-1) HF, diluted to 2 mL, and the solutions thus obtained are analyzed by quadrupole ICP-MS. This method avoids analyte elution from the sorbent. This "dispersed particle extraction" approach yielded a run-to-run relative standard deviation ≤ 5 % for Pt and ≤ 4 % for Pd (at 0.1 ng mL(-1), n = 4 road dust digests). Method detection limits (expressed as concentrations in the dust samples) are 2 and 1 ng g(-1) for Pt and Pd, respectively. The method was validated by analysis of a reference material (BCR CRM 723) and applied to the analysis of road dust samples collected in downtown Vienna. Pt and Pd concentrations in samples collected in summer and in winter were compared, with concentrations ranging from 205 to 1445 ng g(-1) for Pt and from 201 to 1230 ng g(-1) for Pd. Graphical AbstractMesoporous silica microparticles (μPs) functionalized with quarternary amino groups were used for isolating platinum and palladium from aqueous road dust digests. The μPs were suspended directly in the aqueous digests, and the analyte-loaded μPs were analyzed using "dispersed particle extraction".

No MeSH data available.