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Ships moving species across the oceans mix marine communities throughout latitudes. The introduction of new species may be changing the ecosystems even in remote islands. In tropical Pacific islands where maritime traffic is principally local, eDNA metabarcoding and barcoding revealed 75 introduced species, accounting in average for 28% of the community with a minimum of 13% in the very remote Rangiroa atoll. The majority of non-native species were primary producers -from diatoms to red algae, thus the ecosystem is being transformed from the bottom. Primary producers were more shared among sites than other exotics, confirming ship-mediated dispersal in Pacific marine ecosystems. Limited alien share and an apparent saturation of aliens (similar proportion in ports of very different size) suggests the occurrence of “alien drift” in port communities, or random retention of newly introduced aliens that reminds genetic drift of new mutations in a population.The main objectives of this work were the acquisition of new data on floating marine macro litter (FMML) and natural floating objects in the Arctic seas, an initial assessment of the level of pollution by FMML and an analysis of potential sources. The results of this study present the first data on FMML distribution in Russian Arctic shelf seas in relation to oceanographic conditions (i.e. position of water masses of different origin as described by temperature, salinity, dissolved oxygen and pH). The main finding of this study is that FMML was found only in the water of Atlantic origin, inflowing from the Barents Sea, where FMML average density on the observed transects was 0.92 items/ km2. Eastern parts of the study, Kara Sea, Laptev Sea and East Siberian Sea were practically free from FMML. No input from rivers was detected, at least in autumn, when the observations were performed.Multiple-open-tubular columns enabling transverse diffusion (MOTTD) are made of straight, parallel, and cylindrical flow channels separated by a mesoporous stationary phase. In Part 1, a model of band broadening along MOTTD columns accounting for longitudinal diffusion, the trans-channel velocity bias, and mass transfer resistance in the stationary phase was proposed and validated. In this Part 2, the model is completed by considering the impact of short-range inter-channel velocity biases on the MOTTD plate number. These velocity biases are caused by the wide distribution of the channel diameters. Different ratios, ρ, of the average inner diameter, 2(1+RSD)) arranged at the nodes of a hexagonal compact array. The completed model of band broadening in MOTTD columns reveals that the RSD of the channel diameters has only a moderate impact on the optimum plate number of MOTTD columns the relative increase of the minimum plate height do not exceed 30% even for the largest RSDs. However, when the mass transfer of the analyte is governed by its slow rate of transverse diffusion across the MOTTD column, the plate height can be increased by up to 100% at high average velocities. Regarding the best trade-off between analysis speed and column performance at a fixed pressure drop of 400 bar, irrespective of the zone retention factor and RSD of the distribution of the channel diameters, the fastest analyses are recommended for MOTTD columns having a small structural parameter ρ. In contrast, for the longest analysis times, the largest values of ρ are required to maximize the performance of MOTTD columns.Interest in the quantification of highly polar substances in crops has noticeably increased in the last five years. This study was designed to assess quantification of six polar residues, chlorate, ethephon, fosetly-aluminium (fosetyl-Al), glyphosate, phosphonic acid and perchlorate. A total of 2513 pomegranate samples intended for export from Turkey were analysed using the Quick Polar Pesticides (QuPPe) method. ARV-110 The method was in-house validated with very good performance results. The limits of quantification (LOQs) for residues were much lower than the respective EU Maximum Residue Levels (MRLs). Phosphonic acid was detected in 38.5% of pomegranate samples at quantifiable concentrations, calculated as fosetyl-Al. The concentrations ranged between 0.005 and 12.9 mg kg-1. The 20% of pomegranate samples showed fosetyl-Al levels above the EU MRL of 2 mg kg-1. Other polar residues were not detected in any pomegranate samples. This is the first report about highly polar pesticides in pomegranates cultivated in Turkey.Phytotoxins are plant secondary metabolites. They have recently been considered as chemicals of emerging concern (CECs) and there is a growing interest in their environmental fate and potential threat to public health. Dedicated target and non-target screening (NTS) analysis of phytotoxins in environmental samples are sparse, meanwhile phytotoxins are rarely detected in NTS-based analysis due to lack of an efficient methodology. Development of new analytical measurement methods is therefore highly needed. In this study, we for the first time investigated key parameters of reversed phase liquid chromatography-high resolution mass spectrometry (RPLC-HRMS) for five major classes of phytotoxins (alkaloids, steroids, terpenoids, flavonoids and aromatic polyketides) in environmental matrices; the investigation included analytical conditions which have not yet been explored by others, e.g. ionization at alkaline pH above 9. As the outcome we established a new analytical method for target/suspect screening and NTS of phytotoxins in the environment, which significantly improved the detection sensitivity with up to 40 times compared to previous methods, and enabled the discovery of over 30 phytotoxins in a NTS-based environmental study. We also observed that the negative ionization of phenols could be facilitated by the number of hydroxyl groups on the ring rather than their position of substitution. This study is of interest for a better fundamental understanding of the behavior of phytotoxins in LC-MS. Dedicated target/suspect screening and NTS methods will facilitate a better risk characterization of phytotoxins in the environment and stimulate implementation of new public regulation on phytotoxins.