A fully automated simultaneous single-stage separation of Sr, Pb, and Nd using DGA Resin for the isotopic analysis of marine sediments.

A novel, fast and reliable sample preparation procedure for the simultaneous separation of Sr, Pb, and Nd has been developed for subsequent isotope ratio analysis of sediment digests. The method applying a fully automated, low-pressure chromatographic system separates all three analytes in a single-stage extraction step using self-packed columns filled with DGA Resin. The fully automated set-up allows the unattended processing of three isotopic systems from one sediment digest every 2 h, offering high sample throughput of up to 12 samples per day and reducing substantially laboratory manpower as compared to conventional manual methods. The developed separation method was validated using the marine sediment GBW-07313 as matrix-matched certified reference material and combines quantitative recoveries (>90% for Sr, >93% for Pb, and >91% for Nd) with low procedural blank levels following the sample separation (0.07 µg L-1 Sr, 0.03 µg L-1 Pb, and 0.57 µg L-1 Nd). The average δ values for Sr, Pb, and Nd of the separated reference standards were within the certified ranges (δ (87Sr/86Sr)NIST SRM 987 of -0.05(28) ‰, δ(208Pb/206Pb)NIST SRM 981 of -0.21(14) ‰, and δ(143Nd/144Nd)JNdi-1 of 0.00(7) ‰). The DGA Resin proved to be reusable for the separation of >10 sediment digests with no significant carry-over or memory effects, as well as no significant on-column fractionation of Sr, Pb, and Nd isotope ratios. Additional spike experiments of NIST SRM 987 with Pb, NIST SRM 981 with Sr, and JNdi-1 with Ce revealed no significant impact on the measured isotopic ratios, caused by potential small analyte peak overlaps during the separation of Sr and Pb, as well as Ce and Nd.

An analytical strategy for challenging members of the microplastic family: Particles from anti-corrosion coatings.

Potentially hazardous particles from paints and functional coatings are an overlooked fraction of microplastic (MP) pollution since their accurate identification and quantification in environmental samples remains difficult. We have applied the most relevant techniques from the field of microplastic analysis for their suitability to chemically characterize anti-corrosion coatings containing a variety of polymer binders (LDIR, Raman and FTIR spectroscopy, Py-GC/MS) and inorganic additives (ICP-MS/MS). We present the basis of a possible toolbox to study the release and fate of coating particles in the (marine) environment. Our results indicate that, due to material properties, spectroscopic methods alone appear to be unsuitable for quantification of coating/paint particles and underestimate their environmental abundance. ICP-MS/MS and an optimized Py-GC/MS approach in combination with multivariate statistics enables a straightforward comparison of the multi-elemental and organic additive fingerprints of paint particles. The approach can improve the identification of unknown particles in environmental samples by an assignment to different typically used coating types. In future, this approach may facilitate allocation of emission sources of different environmental paint/coating particles. Indeed, future work will be required to tackle various remaining analytical challenges, such as optimized particle extraction/separation of environmental coating particles.

Release of Ammunition-Related Compounds from a Dutch Marine Dump Site.

After World War II, large amounts of ammunition were dumped in surface waters worldwide, potentially releasing harmful and toxic compounds to the environment. To study their degradation, ammunition items dumped in the Eastern Scheldt in The Netherlands were surfaced. Severe damage due to corrosion and leak paths through the casings were observed, making the explosives in the ammunition accessible to sea water. Using novel techniques, the concentrations of ammunition-related compounds in the surrounding seabed and in the seawater were analyzed at 15 different locations. In the direct vicinity of ammunition, elevated concentrations of ammunition-related compounds (both metals and organic substances) were found. Concentrations of energetic compounds ranged from below the limit of detection (LoD) up to the low two-digit ng/L range in water samples, and from below the LoD up to the one-digit ng/g dry weight range in sediment samples. Concentrations of metals were found up to the low microgram/L range in water and up the low ng/g dry weight in sediment. However, even though the water and sediment samples were collected as close to the ammunition items as possible, the concentrations of these compounds were low and, as far as available, no quality standards or limits were exceeded. The presence of fouling, the low solubility of the energetic compounds, and dilution by the high local water current were concluded to be the main causes for the absence of high concentrations of ammunition-related compounds. As a conclusion, these new analytical methods should be applied to continuously monitor the Eastern Scheldt munitions dump site.

Assessing the chemical anthropocene - Development of the legacy pollution fingerprint in the North Sea during the last century.

The North Sea and its coastal zones are heavily impacted by anthropogenic activities, which has resulted in significant chemical pollution ever since the beginning of the industrialization in Europe during the 19th century. In order to assess the chemical Anthropocene, natural archives, such as sediment cores, can serve as a valuable data source to reconstruct historical emission trends and to verify the effectiveness of changing environmental legislation. In this study, we investigated 90 contaminants covering inorganic and organic pollutant groups analyzed in a set of sediment cores taken in the North Seas' main sedimentation area (Skagerrak). We thereby develop a chemical pollution fingerprint that records the constant input of pollutants over time and illustrates their continued great relevance for the present. Additionally, samples were radiometrically dated and PAH and PCB levels in porewater were determined using equilibrium passive sampling. Furthermore, we elucidated the origin of lead (Pb) contamination utilizing non-traditional stable isotopic analysis. Our results reveal three main findings: 1. for all organic contaminant groups covered (PAHs, OCPs, PCBs, PBDEs and PFASs) as well as the elements lead (Pb) and titanium (Ti), determined concentrations decreased towards more recent deposited sediment. These decreasing trends could be linked to the time of introductions of restrictions and bans and therefor our results confirm, amongst possible other factors, the effectiveness of environmental legislation by revealing a successive change in contamination levels over the decades. 2. concentration trends for ΣPAH and ΣPCB measured in porewater correspond well with the ones found in sediment which suggests that this method can be a useful expansion to traditional bulk sediment analysis to determine the biologically available pollutant fraction. 3. Arsenic (As) concentrations were higher in younger sediment layers, potentially caused by emissions of corroded warfare material disposed in the study area after WW II.

Zinc isotopic variation of water and surface sediments from the German Elbe River.

Recent studies suggested the use of the isotopic composition of Zn as a possible tracer for anthropogenic Zn emissions. Nevertheless, studies mainly focused on sampling areas of a few km2 with well-characterized anthropogenic Zn emissions. In contrast, this study focused on analyzing a large sample set of water and sediment samples taken throughout the course of the Elbe River, a large, anthropogenically impacted river system located in Central Europe. The primary objective was to evaluate the use of the isotopic composition of Zn to trace anthropogenic Zn emission on a large regional scale. In total 18 water and 26 surface sediment samples were investigated, covering the complete course of over 700 km of the German Elbe between the German/Czech border and the German North Sea, including six tributaries. Stable isotope abundance ratios of Zn were assessed by multi-collector inductively coupled plasma mass spectrometry (MC ICP-MS) in water filtrates (<0.45 µm) and total digests of the sieved surface sediment fraction (<63 µm) after analyte/matrix separation using Bio-Rad AG MP-1 resin via a micro-column approach and application of a 64Zn/67Zn double spike. Measured isotopic compositions of δ66Zn/64ZnIRMM-3702 ranged from -0.10 ‰ to 0.32 ‰ for sediment samples, and from -0.51 ‰ to 0.45 ‰ for water samples. In comparison to historical data some tributaries still feature high mass fractions of anthropogenic Zn (e.g. Mulde, Triebisch) combined with δ66Zn/64ZnIRMM-3702 values higher than the lithogenic background. The dissolved δ66Zn/64ZnIRMM-3702 values showed a potential correlation with pH. Our results indicate that biogeochemical processes like absorption may play a key role in natural Zn isotopic fractionation making it difficult to distinguish between natural and anthropogenic processes.