Influence of the emission of the platinum group elements on the environment

Wprowadzenie do powszechnego użytku katalizatorów samochodowych spowodowało wzrost emisji metali z grupy platynowców (PGE) do środowiska. Podwyższony poziom zawartości platyny, palladu i rodu jest obserwowany szczególnie w okolicach dużych szlaków komunikacyjnych, rzadko jednak przekracza 1 μg g-1. Celem pracy doktorskiej było określenie wpływu, jaki pierwiastki z tej grupy wywierają na środowisko. Aby to było możliwe konieczne jest dysponowanie metodami gwarantującymi zarówno oznaczanie całkowitych zawartości analitów na odpowiednich poziomach stężeń, jak i śledzenie przemian jakim ulegają i identyfikację ich form chemicznych. Aby uzyskane wyniki oznaczeń były wiarygodne należy szczególną uwagę zwrócić na sposób przygotowania badanych materiałów do analizy. Pod względem analitycznym, oznaczanie śladowych ilości platyny, rodu czy palladu w próbkach środowiskowych nie jest zadaniem prostym. Złożoność matrycy próbek oraz niski poziom stężeń sprawiają, że metody oznaczeń muszą charakteryzować się odpowiednio niskimi granicami oznaczalności. Często w procedurze analitycznej wprowadza się dodatkowy etap zatężania analitów i uproszczenia matrycy próbki. W ramach prowadzonych badań zoptymalizowano procedury roztwarzania próbek gleb i piasków kwarcowych z wykorzystaniem mieszaniny kwasów HNO3 i HCl. W oparciu o wyniki uzyskane dla certyfikowanego materiału odniesienia – pyłu drogowego BCR-723 wykazano efektywne przeprowadzenie PGE do roztworu. Do wydzielania analitów z matrycy wykorzystano metodę ekstrakcji do fazy stałej. W trakcie badań zastosowano sorbenty kationo- i anionowymienne oraz eluenty o różnej sile elucyjnej: 0,1 mol L-1 tiomocznik w 0,1 mol L-1 HCl, 2 mol L-1 HCl, 0,025-0,053 mol L-1 bufor amonowy. Opracowane procedury przygotowania próbek zastosowano do monitorowania PGE w próbkach gleb i piasków kwarcowych, pobieranych z poletek monitoringowych rozmieszczonych wzdłuż ciągów komunikacyjnych i eksponowanych na zanieczyszczenia związane z ruchem drogowym. Szczególną uwagę zwrócono na możliwość zastosowania w oznaczeniach metody woltamperometrii inwersyjnej z adsorpcyjnym zatężaniem (AdSV), która, ze względu na niskie granice oznaczalności może być alternatywą do metody spektrometrii mas z plazmą indukcyjnie sprzężoną (ICP MS). Na podstawie uzyskanych wyników wykazano wpływ ruchu drogowego na wzrastające skażenie środowiska oraz wskazano katalizatory samochodowe, jako główne emitery pierwiastków z grupy platynowców. Odkładanie się PGE w glebach sprawia, że mogą być one pobierane i akumulowane przez rośliny, co może powodować zaburzenia ich prawidłowego funkcjonowania. W oparciu o materiał roślinny pozyskany w ramach upraw hydroponicznych określono wpływ platyny, palladu i rodu na rozwój gorczycy białej (Sinapis alba L.). Rośliny narażone na stres związany z obecnością różnych soli i nanocząstek PGE zostały scharakteryzowane pod kątem całkowitej zawartości metali pobranych z pożywki i przetransportowanych do części nadziemnych (ICP MS), obecności nanocząstek w wybranych tkankach (SP ICP MS, TEM), jak i tworzenia kompleksów z ligandami obecnymi lub syntezowanymi de novo w roślinie. Powstałe w tkankach fitochelatyny (PC2, PC3 i PC4) zidentyfikowano metodą wysokosprawnej chromatografii cieczowej z detekcją fluorescencyjną (HPLC FLD) oraz spektrometrią mas z jonizacją przez elektrorozpraszanie (ESI MS). Dodatkowo dzięki wykorzystaniu metody SEC ICP MS, wykryto i rozdzielono grupy związków palladu powstających w komórkach Sinapis alba L. Z kolei zastosowanie metody HILIC ESI MS umożliwiło zidentyfikowanie wybranych połączeń Pd z ligandami organicznymi, jak histydyna i nikotianamina, odpowiedzialnymi za procesy detoksykacji metali.Introduction of car catalysts for general use caused an increase in emissions of platinum group elements (PGEs) to the environment. The increased level of platinum, palladium and rhodium is observed, especially in the vicinity of main communication routes, but still, rarely exceeds 1 μg g-1. The aim of the doctoral thesis was to determine an impact which PGEs may have on the environment. To make that possible, it's necessary to develop procedures, guaranteeing both, determination of the total content of analytes at appropriate concentration levels, as well as monitoring the changes they undergo and identification of their chemical forms. In order to get the reliable results, particular attention should be paid to the proper way of sample preparation before analysis. The determination of trace amounts of platinum, rhodium or palladium in environmental samples is not a simple task. The complexity of the sample matrix and the low concentration level of analytes cause that the determination methods must have sufficiently low limits of quantification. Often an additional step of analytes pre-concentration and separation from the matrix is introduced in the analytical procedure. As a part of the conducted research, the digestion procedures of soil and quartz sands samples, using the mixture of HNO3 and HCl acids, were optimized. Based on the results obtained for certified reference material (BCR-723; road dust) the possibility of efficient analytes transfers into the solution was proven. To isolate analytes from the matrix the solid phase extraction method was suggested. During the experiments, cation and anion exchange sorbents, as well as the eluents of various elution strength were used: 0.10 mol L-1 thiourea in 0.10 mol L-1 HCl, 2.0 mol L-1 HCl, 0.025-0.053 mol L-1 ammonium buffer. Developed sample preparation procedures were used to monitor PGEs in soil and quartz sands samples received from the monitoring plots distributed along high-ways and exposed to traffic-related contamination. Particular attention was paid to the possibility of using adsorptive stripping voltammetry (AdSV), which, due to low limits of quantification, can be an alternative method to inductively coupled plasma mass spectrometry (ICP MS). Based on the results obtained, the influence of road traffic on the increasing environmental pollution was proven, along with the indication of car catalysts as main emitters of the platinum group elements. The deposition of PGEs in soils makes that they can be taken up and accumulated by plants, which may cause disturbances in their proper functioning. The influence of platinum, palladium and rhodium on the growth of white mustard (Sinapis alba L.) was defined based on the plant material obtained from hydroponic cultivation. The plants, exposed to stress from the presence of various salts and nanoparticles of PGEs, have been characterized for the total content of metals taken from the nutrient solution and transported to aboveground organs (ICP MS), the presence of nanoparticles in selected tissues (SP ICP MS, TEM) and the formation of complexes with ligands present or de novo synthesized in the plant. The phytochelatins (PC2, PC3 and PC4), formed in plant cells, were identified by high-performance liquid chromatography with fluorescence detection (HPLC FLD) and electrospray ionization mass spectrometry (ESI MS). Additionally, thanks to the use of the SEC ICP MS method, some palladium compounds formed in Sinapis alba L. cells were detected and separated. The application of HILIC ESI MS method enabled identification of several Pd complexes with organic ligands, like histidine and nicotianamine, responsible for metal detoxification processes

Analytical chemistry in investigation and protection of the environment

The main goal of studies carried in our reasearch group – analytical chemistry in investigation and protection of the environment is the evaluation of the impact of human activity on environmental pollution, and creation of analytical procedures that can be applied in environmental analysis. Detailed description of our research can be found on webpage http://www.chem.uw.edu.pl/labs/pcas. In this paper we would like to present only a few topics and analytical challenges that we were dealing with during the last years. The application of anodic and cathodic stripping voltammetry for trace analysis of hazardous metals (cadmium, lead, thallium, platinum, rhodium) in natural samples is described [4–6]. Voltammetry is also presented as a tool used in speciation analysis, which is particularly important in the case of elements which toxicity and assimilation depends on chemical form of the element that is present in the environment (e.g. As) [8]. Attention is also paid to fractionation, which is a specific case of speciation analysis, extremely important for evaluation of mobility and bioavailability of harmful or nutritious substances from soil. As environmental monitoring often requires carrying measurements at trace levels, it might be necessary to preconcentrate the analytes or simplify the composition of the sample before the analysis. For such purposes solid phase extraction (SPE) is widely used and frequently applied. Another analytical task presented in this work is recognition of the defense mechanisms developed by hyperaccumulating plants, e.g. white mustard. This species was investigated for synthesis of phytochelatins – sulphur-rich polipeptides induced by high concentrations of As, Tl, Cd, Pt, Pd and Rh [14]. It is worth noting that plant species that are able to cumulate high amounts of xenobiotics can be used for phytoremediation, which is one of so called “green technologies”, used for restitution of polluted environment, particularly soil [19]

Speciation of essential nutrient trace elements in coconut water

International audienceCoconut 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 (ICP MS), and hydrophilic interaction liquid chromatography (HILIC)electrospray-Orbitrap MS. The metal species identified included: iron complexes with citrate and malate: Fe III (Cit) 3 (Mal), Fe III (Cit) 2 (Mal) 2 , Fe III (Mal) 2 , glutamine: Fe III (Glu) 2 and nicotianamine: Fe II (NA); copper complexes with phenylanine: Cu II (Phe) 2 and Cu II (Phe) 3 and nicotianamine: Cu II (NA); zinc complexes with citrate: Zn II (Cit) 2 and nicotianamine Zn II (NA) and manganese complex with asparagine Mn II (Asp) 2. The contributions of the individual species to the total elements concentrations could be estimated by HILIC-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

International audienceAg, 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

Screening for Antibiotics and Their Degradation Products in Surface and Wastewaters of the POCTEFA Territory by Solid-Phase Extraction-UPLC-Electrospray MS/MS

A method based on UPLC-MS/MS (ultraperformance liquid chromatography—tandem mass spectrometry) was optimized for the analysis of a broad set of antibiotics and their metabolites in surface and wastewaters after their preconcentration by solid-phase extraction (SPE). The method was applied to the monitoring of the river basin of the POCTEFA (Interregional Programme Spain-France-Andorra) territory (Spain and France) in frame of a sampling campaign (2020–2021) including 40 sampling points, 28 of them corresponding to surface waters and 12 to wastewaters. In total, 21 antibiotics belonging to different families, i.e., ciprofloxacin, sulfamethoxazole, trimethoprim, azithromycin, and their metabolites were detected. A higher overall antibiotic contamination was observed in the Spanish part of the POCTEFA territory. Several metabolites of the target antibiotics, some of them supposed to be more toxic than their parent compounds, were identified in the entire sampling network. Fluoroquinolones and sulfamethoxazole, as well as their metabolites, presented the highest detection frequency both in wastewaters and surface waters, and, consequently, should be considered as target compounds in the monitoring of the water resources of the POCTEFA territory

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

International audiencePalladium 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