A new yet little understood threat to our ecosystems is microplastics.

A novel method, which enables the determination of fungal infection with Fusarium graminearum on corn within minutes, is presented. The ground sample was sieved and the particle size fraction between >250 and 100 microm was used for mid-infrared/attenuated total reflection (ATR) measurements. The sample was pressed onto the ATR crystal, and reproducible pressure was applied. After the spectra were recorded, they were subjected to principle component analysis (PCA) and classified using cluster analysis. Observed changes in the spectra reflected changes in protein, carbohydrate, and lipid contents. Ergosterol (for the total fungal biomass) and the toxin deoxynivalenol (DON; a secondary metabolite) of Fusarium fungi served as reference parameters, because of their relevance for the examination of corn based food and feed. The repeatability was highly improved by sieving prior to recording the spectra, resulting in a better clustering in PCA score/score plots. The developed method enabled the separation of samples with a toxin content of as low as 310 microg/kg from noncontaminated (blank) samples. Investigated concentration ranges were 880-3600 microg/kg for ergosterol and 310-2596 microg/kg for DON. The percentage of correctly classified samples was up to 100% for individual samples compared with a number of blank samples.

An analytical method has been developed for the assignment of recent and archaeological wood tar pitches to the species of trees used for their preparation. It Incorporates the prepurlflcatlon by Kugelrohr distillation and solid-phase extraction followed by gas chromatography/mass spectrometry analysis. Distribution patterns of volatile, thermostable triterpenoids and steroids characterizing the biological origin of the pitches are evaluated by principal component analysis (PCA) and discriminant component analysis (DCA) of the data. Quantities of 10-100 mg of archaeological material can thus be characterized. Fourteen archaeological samples have been identified as birch bark pitches by comparison with recent pitches of known origin. In addition 28 substances present In recent barks and recent pitches could be Identified showing that the method developed can also be applied to the chemotaxonomy of broad-leaved trees.

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