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Are substances more persistent than test systems lead to believe? Non-extractable residues: experimental examination of suitable extraction methods in view of a long-term risk for the environment

In transformation tests with organic substances in soil non-extractable residues (NER) are formed which remain there as residues. Some can be released again into the environment in the long-term and should be considered in the persistent assessment. Besides substances properties and soil characteristics the proportion of NER strongly depends on the extraction procedure. Within the European authorisation procedures, there is no precise and generally applicable definition of how NERs are to be determined and characterised. In this project a widely applicable standardised extraction procedure for the determination of non-extractable residues was developed to improve the comparability of NER data. Further extraction methods for the characterisation of reversibly bound residues such as ⁠ EDTA ⁠ extraction and silylation are discussed. The report is aimed at regulators, industry and experts from science and research. Veröffentlicht in Texte | 133/2022.

Extraction of antimony and arsenic from fresh and freeze-dried plant samples as determined by HG-AAS

Krachler, Michael; Emons, Hendrik Fresenius' Journal of Analytical Chemistry 368 (2000), 7, 702 - 707 Six extraction media (acetic acid, EDTA, tetrabutylammonium hydroxide, NaOH, MeOH/H 2 O, acetonitrile/H 2 O) were tested for their ability to extract antimony (Sb) and arsenic (As) from freeze-dried popular leaves, pine shoots and spruce shoots, as well as from a peat matrix. Additionally, the extraction efficiency of Sb and As in fresh and freeze-dried elder leaves and poplar leaves was compared. Total concentrations of Sb and As of aliquots (~220 mg) of the freeze-dried samples were analysed by flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS) after open vessel digestion with adequate mixtures of nitric, sulfuric, hydrochloric, and perchloric acid. Three reference materials GBW 07602 Bush Branches and Leaves, GBW 07604 Poplar Leaves, and SRM 1575 Pine Needles were analysed with every batch of samples to ensure the accuracy and precision of the applied analytical procedures. The use of hydrofluoric acid in the digestion mixture leads to distinctly lower As values (down to 40%) than actual concentrations in the investigated plant materials. Extraction efficiencies were generally low and lower for Sb than for As. Solutions of 0.66 mol L -1 NaOH liberated highest amounts of Sb with ~10% for popular leaves, and ~19% each for pine shoots and spruce shoots. Distinctly higher concentrations of As in NaOH extracts of popular leaves (22%), pine shoots (32%), and spruce shoots (36%) were quantified. Extraction experiments resulted in yields of 7-9% from fresh elder and popular leaves, respectively, and 8-13% for freeze-dried samples for Sb. The corresponding values for As were 10-35% for the fresh material and 7-37% for the freeze-dried samples. doi:10.1007/s002160000578

GW-Messstelle RGW Köln WE 061 UW (Betreibermessstellen)

Grundwassermessstellen dienen der Überwachung des Grundwassers. Dieser Datensatz enthält die Messdaten der Messstelle RGW Köln WE 061 UW. Wasserart: reines Grundwasser

Vertikalfilterbrunnen E SW Kleve Br.5 (RWÜ (Messstelle f. GWÜ geeignet))

Grundwassermessstellen dienen der Überwachung des Grundwassers. Dieser Datensatz enthält die Messdaten der Messstelle E SW Kleve Br.5. Wasserart: reines Grundwasser

Vertikalfilterbrunnen E SW Kleve Br.9 (RWÜ (Messstelle f. GWÜ geeignet))

Grundwassermessstellen dienen der Überwachung des Grundwassers. Dieser Datensatz enthält die Messdaten der Messstelle E SW Kleve Br.9. Wasserart: reines Grundwasser

GW-Messstelle BS 1 ML -15,50 NOR (Grundwassergüteüberwachung)

Grundwassermessstellen dienen der Überwachung des Grundwassers. Dieser Datensatz enthält die Messdaten der Messstelle BS 1 ML -15,50 NOR. Wasserart: reines Grundwasser

GW-Messstelle BS 1 ML -08,00 NOR (Grundwassergüteüberwachung)

Grundwassermessstellen dienen der Überwachung des Grundwassers. Dieser Datensatz enthält die Messdaten der Messstelle BS 1 ML -08,00 NOR. Wasserart: reines Grundwasser

GW-Messstelle BS 1 ML -10,50 NOR (Grundwassergüteüberwachung)

Grundwassermessstellen dienen der Überwachung des Grundwassers. Dieser Datensatz enthält die Messdaten der Messstelle BS 1 ML -10,50 NOR. Wasserart: reines Grundwasser

GW-Messstelle BS 1 ML -05,50 NOR (Grundwassergüteüberwachung)

Grundwassermessstellen dienen der Überwachung des Grundwassers. Dieser Datensatz enthält die Messdaten der Messstelle BS 1 ML -05,50 NOR. Wasserart: reines Grundwasser

GW-Messstelle BS 1 ML -13,00 NOR (Grundwassergüteüberwachung)

Grundwassermessstellen dienen der Überwachung des Grundwassers. Dieser Datensatz enthält die Messdaten der Messstelle BS 1 ML -13,00 NOR. Wasserart: reines Grundwasser

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