Sample preparation - A crucial step to distinguish metallic and ionic platinum forms and their mobility in soil.

The study is focused on one of the technology-critical elements (TCEs), Pt in the context of distinguishing ionic from metallic forms and assessing sorption capacity of soil. Solid-liquid extraction, cross-comparison of the results of two determination techniques and two decomposition methods enable quantitative determination of the ionic form and, indirectly, NPs in soil and plants. Information about ionic form is obtained after sample digestion with conc. HNO3 and AdSV determination, and total Pt content is determined after digestion using mixture of conc. HNO3 and conc. HCl. The recovery of Pt was in the range 99-110 % for both forms. The mobility (0.43 mol L-1 HAc) of Pt-NPs and Pt (II) was below 1 % even in the presence of citrates (after 2 month incubation). The long-term sorption study indicated that Pt retention (both forms) in the organic soil is related to formation of organic complexes, and the equilibrium is achieved after 2 days. When the soil is enriched in Fe2O3, stronger sorption is observed up to 2 days for both Pt forms (the mobility is 9-14 pp. lower), to finally achieve similar sorption as without modification, reaching 89/90 % for incubation with DI water, and 81/85 % with citrates. The addition of biocarbon/biochar does not play an important role in immobilization of Pt (II) and Pt-NPs.

Quantitative Determination of Iron-Siderophore Complexes in Peat by Isotope-Exchange Size-Exclusion UPLC-Electrospray Ionization High-Resolution Accurate Mass (HRAM) Mass Spectrometry.

A method was developed for the quantification of iron-siderophore complexes by electrospray high-resolution accurate mass (HRAM) mass spectrometry (MS) without the need for authentic standards. The bulk of iron-siderophore complexes was purified by solid-phase extraction (SPE) and concentrated by evaporation. The individual complexes were identified by fast size-exclusion chromatography (FastSEC)-Orbitrap MSn on the basis of the exact molecular mass (±1 ppm) and MS2 or MS3 fragmentation. Their capability to readily exchange the natural 56Fe for the added 58Fe was demonstrated by SEC with ICP MS and ESI MS detection. The method was applied to the analysis of peat sampled in the eastern part of the French Pyrenean mountains. Nineteen siderophores belonging to four different classes were identified and quantified. The results were validated using ICP MS detection of iron by matching the sum of iron complexes determined by isotope exchange-ESI MS within each peak observed by FastSEC-ICP MS.

Speciation of metals in indigenous plants growing in post-mining areas: Dihydroxynicotianamine identified as the most abundant Cu and Zn ligand in Hypericum laricifolium.

Ag, As, Cu, Pb and Zn were found to be the principal metallic contaminants of a post-mining area of Peru (Hualgayoc, Cajamarca). Study of metal distribution amongst roots, stems, and leaves of four indigenous hypertolerant plant species, Arenaria digyna, Puya sp., Hypericum laricifolium, Nicotiana thyrsiflora indicated significant translocation of Zn (0.6 < TF ≤ 10.0) and Cu (0.4 < TF ≤ 6.5) into aerial plant organs and substantial water-extractable fraction (20-60%) of these metals, except for A. digyna (root and stems). A study of the metal speciation by ultrahigh-performance size-exclusion (fast-SEC) and hydrophilic ion interaction (HILIC) liquid chromatography with dual ICP (inductively coupled plasma) and electrospray (ESI) Orbitrap MS detection revealed the presence of nicotianamine and deoxymugineic acid copper and zinc complexes in roots, stem and leaves of N. thyrsiflora and Puya sp., and nicotianamine alone in A. digyna. A previously unreported compound, dihydroxy-nicotianamine was identified as the most abundant Cu and Zn ligand in H. laricifolium. The presence of arsenobetaine and an arsenosugar was confirmed by ESI MS. Ag and Pb were hardly translocated to leaves and were found as high molecular species; one of the Pb-containing species co-eluted in fast-SEC-ICP MS with rhamnogalacturonan-II-Pb complex commonly found in in the walls of plants.

Search for effective eluent for Pd separation on ion-exchange sorbent before voltammetric determination.

Determination of Pd traces in environmental samples is still a challenging analytical task. The aim of this study was to propose an efficient system (i.e. ion-exchange resin and eluent) for Pd elution from SPE column after the analyte preconcentration. Moreover, the search was focused on solvents that would not interfere voltammetric determination of Pd, as well as ICP-MS analysis. Five ion-exchange sorbents were compared in terms of effective Pd separation from matrix components when using different eluents. The highest recovery (up to 91%) of palladium was obtained for Dowex 1 and ammonium buffer as the eluent. This solution not only provides relatively high palladium elution efficiency but also allows both voltammetric and ICP-MS determinations, without any additional sample preparation. It was proven that the proposed procedure including SPE separation and determination with AdSV and/or ICP-MS could be used for quantitative Pd measurement in environmental samples, such as quartz sand used for the monitoring of Pd emission in the areas of high traffic density.

Speciation of essential nutrient trace elements in coconut water.

Coconut water (Cocos Nucifera) is shown to be a source of essential elements present in the form of low-molecular weight stable complexes known for their bio-availability. The total element concentrations were in the range of 0.2-2.7, 0.3-1, 3-14 and 0.5-2 ppm for Fe, Cu, Mn, and Zn, respectively, and varied as a function of the origin of the nut and its maturity. Speciation was investigated by size-exclusion chromatography - inductively coupled plasma mass spectrometry (ICPMS), and hydrophilic interaction liquid chromatography (HILIC) - electrospray-OrbitrapMS. The metal species identified included: iron complexes with citrate and malate: FeIII(Cit)3(Mal), FeIII(Cit)2(Mal)2, FeIII(Mal)2, glutamine: FeIII(Glu)2 and nicotianamine: FeII(NA); copper complexes with phenylanine: CuII(Phe)2 and CuII(Phe)3 and nicotianamine: CuII(NA); zinc complexes with citrate: ZnII(Cit)2 and nicotianamine ZnII(NA) and manganese complex with asparagine MnII(Asp)2. The contributions of the individual species to the total elements concentrations could be estimated by HILIC - ICP MS.

A chemical speciation insight into the palladium(ii) uptake and metabolism by Sinapis alba. Exposure to Pd induces the synthesis of a Pd-histidine complex.

Palladium is recognized as a technologically critical element (TCE) because of its massive use in automobile exhaust gas catalytic converters. The release of Pd into the environment in the form of nanoparticles of various size and chemical composition requires an understanding of their metabolism by leaving organisms. We provide here for the first time a chemical speciation insight into the identity of the ligands produced or used by a plant Sinapis alba L. exposed in hydropony to Pd nanoparticles and soluble Pd (nitrate). The analytical method developed was based on the concept of 2D HPLC with parallel inductively coupled plasma mass spectrometry (ICP MS) and electrospray MS detection. Size exclusion chromatography - ICP MS of the plant extracts showed no difference between the speciation of Pd after the exposure to nanoparticles and after that to Pd2+ which indicated the reactivity and dissolution of Pd nanoparticles. A comparative investigation of the Pd speciation in a control plant extract spiked with Pd2+ and of an extract of a plant having metabolized palladium indicated the response of the Sinapis alba by the formation of a Pd-histidine complex. The complex was identified via Orbitrap MS; the HPLC-MS chromatogram produced two peaks at m/z 415.0341 each corresponding to a Pd-His2 complex. An investigation by ion-mobility MS revealed a difference in their collision cross section indicating that the complexes present varied in terms of spatial conformation. A number of other Pd complexes with different ligands (including nicotianamine) circulating in the plant were detected but these ligands were already observed in a control plant and their concentrations were not affected by the exposure to Pd.

Study of the uptake and bioaccumulation of palladium nanoparticles by Sinapis alba using single particle ICP-MS.

In recent years, increased palladium content has been found in the environment, due to its wide use in various fields, especially as catalytic converters. Palladium can be emitted as a range of soluble and insoluble compounds and in the form of palladium nanoparticles (PdNPs). The level of toxicity is equally dependent on concentration and form of palladium and hence, it is important to determine not only the total content of this element, but also its forms of occurrence. This study for the first time investigates the uptake degree and distribution of PdNPs by model plant Sinapis alba, in comparison with a platinum salt (Pd(NO3)2). An enzymatic digestion method which allows the extraction of PdNPs from the different plant tissues without altering their properties was applied. After extraction, samples were analysed by single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) to provide information about the presences of palladium in nanoparticulated or dissolved form, the nanoparticle size and the nanoparticle number concentration. Significant amounts of PdNPs were found even in aboveground organs, but no significant changes in plant morphology were observed. Size distributions of PdNPs found in all tissues presented lower diameters than size distribution of the PdNPs stock suspension, suggesting that bigger nanoparticles are not taken up by the plant. The average size found is in good agreement between the different organs. Moreover, dissolved palladium was found in all samples, with the biggest contribution, in relative terms, observed in leaves followed by stems and roots.

Determination of traces of Pt and Rh in soil and quartz samples contaminated by automobile exhaust after an ion-exchange matrix separation.

Monitoring of PGEs content in the natural samples is a crucial point in the environment science since catalytic car converters have been introduced. In the presented paper application of a very sensitive voltammetric method for determination of traces of Pt and Rh in the environmental samples contaminated by automobile exhausts is discussed. Voltammetric measurements were carried out in the supporting electrolyte containing formaldehyde and semicarbazide. PGEs were separated from the digested solutions of soils or quartz samples, collected from monitoring plots-by applying an ion-exchange resin Cellex-T. Pt was very effectively separated from the matrix approaching nearly 100% recovery after its elution by hydrochloric acid. Moreover the conditions of soil and quartz samples digestion were discussed. To validate the obtained result an independent analytical method-ICP MS was applied and analysis of certified reference material road dust 723-was completed.