Limits...
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.


Related in: MedlinePlus

Schematic of the DPE sample pre-treatment process (black spots: SAX micro-particles). This figure is based on quantitative analyte-recoveries
© Copyright Policy - OpenAccess
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4608980&req=5

Fig2: Schematic of the DPE sample pre-treatment process (black spots: SAX micro-particles). This figure is based on quantitative analyte-recoveries

Mentions: Ten milliliters of sample digest (0.240 mol L−1 HCl) were transferred into a metal-free centrifugation tube. The optimum amount of SAX sorbent material (2 mg) was added in the form of an aqueous suspension and the sample was homogenized in an ultrasonic bath. A first centrifugation step was performed at 17,000×g for 10 min. The particles were found to be strongly compressed onto the walls and the bottom of the centrifuge tube and therefore, it was possible to swiftly decant the supernatant solution (see Fig. 2(1)). For further removal of matrix constituents, the precipitate was re-suspended in 10 mL of 0.240 mol L−1 HCl. After manual shaking and ultrasonic agitation, the centrifugation step was repeated and the supernatant solution discarded (Fig. 2(2)). Thereby, matrix components that remained on the particles during the first decantation-step can be removed. This washing cycle was repeated two more times (Fig. 2(3) and (4)). Finally, the mesoporous particles were destroyed by adding 0.1 mL of a mixture containing 2 mol L−1 HF and 1.2 mol L−1 HCl. After adding indium as internal standard, the solutions were diluted to 2 mL using high purity water (Fig. 2(5)). As schematically depicted in Fig. 2, this procedure yields a stepwise removal/dilution of any matrix constituents that do not bind to the SAX-sorbent material. Contrarily, analytes that are adsorbed onto the sorbent resin remain at constant concentration and finally become pre-concentrated. The theoretical enrichment factor depends on the ratio of starting volume to final volume and was 5.Fig. 2


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)

Schematic of the DPE sample pre-treatment process (black spots: SAX micro-particles). This figure is based on quantitative analyte-recoveries
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4608980&req=5

Fig2: Schematic of the DPE sample pre-treatment process (black spots: SAX micro-particles). This figure is based on quantitative analyte-recoveries
Mentions: Ten milliliters of sample digest (0.240 mol L−1 HCl) were transferred into a metal-free centrifugation tube. The optimum amount of SAX sorbent material (2 mg) was added in the form of an aqueous suspension and the sample was homogenized in an ultrasonic bath. A first centrifugation step was performed at 17,000×g for 10 min. The particles were found to be strongly compressed onto the walls and the bottom of the centrifuge tube and therefore, it was possible to swiftly decant the supernatant solution (see Fig. 2(1)). For further removal of matrix constituents, the precipitate was re-suspended in 10 mL of 0.240 mol L−1 HCl. After manual shaking and ultrasonic agitation, the centrifugation step was repeated and the supernatant solution discarded (Fig. 2(2)). Thereby, matrix components that remained on the particles during the first decantation-step can be removed. This washing cycle was repeated two more times (Fig. 2(3) and (4)). Finally, the mesoporous particles were destroyed by adding 0.1 mL of a mixture containing 2 mol L−1 HF and 1.2 mol L−1 HCl. After adding indium as internal standard, the solutions were diluted to 2 mL using high purity water (Fig. 2(5)). As schematically depicted in Fig. 2, this procedure yields a stepwise removal/dilution of any matrix constituents that do not bind to the SAX-sorbent material. Contrarily, analytes that are adsorbed onto the sorbent resin remain at constant concentration and finally become pre-concentrated. The theoretical enrichment factor depends on the ratio of starting volume to final volume and was 5.Fig. 2

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.


Related in: MedlinePlus