Leaching of PCE-based Superplasticiser from Microfine Cement: a Chemical and Ecotoxicological Point of View

The construction materials industry faces major challenges since 2013 when the European Construction Products Regulation was implemented, especially in the sector of environmentally friendly construction products. This study determined concentrations of leachable inorganic and organic compounds from microfine cement paste with and without superplasticiser addition. Furthermore, the leached superplasticiser amounts were detected via LC-MS. The multi-method approach was supplemented by ecotoxicological assays. Phytotoxicity was tested with white mustard (Sinapis alba) and cress (Lepidium sativum). The mutagenic and genotoxic potential of the leachates was tested with the Ames fluctuation assay and the umuC assay. As leaching protocol, the European horizontal dynamic surface leaching test was used. The cement paste samples with superplasticiser followed the wash-off effect with a total organic carbon release up to 43 mmol/m², whereas the release of samples without superplasticiser was driven by diffusion. The ecotoxicological assays showed a clear time depending behaviour. No cytotoxicity and mutagenicity could be observed; anyhow some leachates show minor genotoxic potential. In all tests, a clear difference between the samples with and without superplasticiser could be detected.This study clearly demonstrates the importance of further studies in the field of leaching of construction products.     

Bestimmung von Insektizid-Rückständen und Prüfung von Dauerbelägen

Ohne Zusammenfassung® eingetragenes Warenzeichen.     

Cryptoxanthin structural isomers in oranges, orange juice, and other fruits

Citrus fruits contain a wide range of bioactive compounds. Their carotenoid fraction is inter alia dominated by structural cryptoxanthin isomers as beta-cryptoxanthin and zeinoxanthin. Both xanthophylls were identified in saponified citrus fruit extracts by comparison to reference compounds extracted from corn and by their typical fragmentation pattern in LC-(APCI)MS analyses. alpha-Cryptoxanthin, another structural cryptoxanthin isomer usually found in carrot leaves, was not identified in the citrus fruits studied. Cryptoxanthin concentrations of direct orange juices (D) and reconstituted juices (C) were compared. Although the respective mean values [beta-cryptoxanthin, 62 (C) versus 110 microg/100 g (D); zeinoxanthin, 22 (C) versus 37 microg/100 g (D)] were statistically distinguishable (P < 0.05%), a doubtless classification is not possible because the concentration ranges overlap. To identify esters of structural cryptoxanthin isomers in native orange juice extracts, four saturated acyl esters were synthesized. LC-(APCI)MS studies revealed for the first time that the dominant acylation partners of both xanthophylls were C12:0, C14:0, and C16:0 in nearly equal amounts of roughly one-third, whereas C10:0 and C18:1 were present at lower extents of 5-14%; other acylation partners were not identified. The presented method is appropriate to gain deeper insight into the pattern of structural cryptoxanthin isomers of citrus fruits. Knowledge of acylated cryptoxanthin isomers may be important in the evaluation of the bioavailability of individual esters in future human digestion studies.     

Antibody titer against bovine viral diarrhea virus (BVDV) in bulk milk samples from Bavaria

A total of 5204 bulk milk samples were tested for antibodies against bovine viral diarrhea virus (BVDV) classified according to the scheme after Alenius. Forty-five percent of the samples from 2002 were classified as class 0 and class 1, 55% as class 2 and 3. 6420 bulk milk samples from 1997 were classified in an independent study in 65.6% class 0 and 1 and 34.4% in class 2 and 3. In class 0 and class 1 farms only very rarely persistent viremic animals have been found, whereas in class 2 and 3 their presence is highly likely. Our studies with non-selected sera defined the serological screening of bulk milk samples as a promising tool for a possible BVDV eradication program in Bavaria.     

Long-term sea-level fluctuations driven by ocean basin dynamics

Earth's long-term sea-level history is characterized by widespread continental flooding in the Cretaceous period (approximately 145 to 65 million years ago), followed by gradual regression of inland seas. However, published estimates of the Late Cretaceous sea-level high differ by half an order of magnitude, from approximately 40 to approximately 250 meters above the present level. The low estimate is based on the stratigraphy of the New Jersey margin. By assimilating marine geophysical data into reconstructions of ancient ocean basins, we model a Late Cretaceous sea level that is 170 (85 to 270) meters higher than it is today. We use a mantle convection model to suggest that New Jersey subsided by 105 to 180 meters in the past 70 million years because of North America's westward passage over the subducted Farallon plate. This mechanism reconciles New Jersey margin-based sea-level estimates with ocean basin reconstructions.