Analitičke metode za određivanje teških metala u tekstilnoj industriji

Heavy metals in textile wastewater represent a major environmental problem, and are a potential danger to human health when present on textiles. Furthermore, the presence of some metals influences the production of textiles. Heavy metals are often used as oxidizing agents, as metal complex dyes, dye stripping agents, fastness improvers, and finishers. Thus, they act as hazardous sources throughout entire textile processing. Toxic effects of heavy metals on humans are well documented. Therefore, it is important to monitor heavy metals throughout the entire production. Today, maximum permissible values for metals in textiles are given by different regulations, according to which the heavy metals have to be determined both qualitatively and quantitatively. Several analytical procedures for the determination of heavy metals were tested for their application on textiles. The advantages and disadvantages of TLC, UV-VIS, GF-AAS, ICP-OES, and ICP-MS methods are discussed.Teški metali u otpadnim vodama tekstilne industrije čine ogroman problem za okoliš, a kada se nalaze na tekstilnim materijalima iskazuju potencijalnu opasnost po ljudsko zdravlje. U tekstilnoj industriji teški se metali vrlo često rabe kao oksidansi, bojila te sredstva za poboljšavanje svojstava postojanosti. S obzirom na to da su toksični učinci teških metala na ljudsko zdravlje danas veoma dobro poznati (Tablica 1), vrlo je važno kontrolirati njihovu prisutnost tijekom proizvodnje i prerade tekstilnih materijala. Maksimalno dopuštene količine teških metala koje se nalaze na tekstilnim materijalima, pa se tijekom uporabe mogu ekstrahirati znojenjem i tako štetno utjecati na zdravlje ljudi, regulirane su različitim standardima (Tablica 2). Prema njima, potrebno je određivati i pratiti metale na materijalima, za što je moguće primijeniti nekoliko različitih analitičkih metoda. U ovom radu razmatrani su prednosti i nedostaci metoda TLC, UV-VIS, GF-AAS, ICP-OES i ICP-MS. Prije analize udjela teških metala na tekstilnim materijalima, uzorke je potrebno pripremiti za analizu. Velika važnost uzorkovanja (Slika 1), priprave i čuvanja uzoraka (tablice 3-4) naglašene su u poglavljima 2.1 - 2.3. Metoda tankoslojne kromatografije opisana u poglavlju 2.4. može se jednostavno i brzo primijeniti za učinkovito razdvajanje i dokazivanje različitih teških metala. Nedostatak te metode su visoke granice detekcije. UV-VIS spektroskopija je također jednostavna analitička metoda za određivanje metala koja zahtijeva pažljivu pripravu uzoraka. Karakteristike UV-VIS određivanja odabranih teških metala prikazane su u Tablici 5. Atomska apsorpcijska spektroskopija (FAAS i GF-AAS) jedna je od najviše upotrebljavanih metoda u analizi metala koja ima niske granice detekcije. Osnovni nedostatak te metode je nemogućnost istodobnog određivanja više elemenata u istom uzorku, kao što je to moguće kod induktivno spregnute plazme. Stoga je i priprava uzorka za analizu AAS-om dugotrajnija te iziskuje veće troškove. Zbog toga danas najprikladnije metode za analizu metala postaju upravo ICP-OES i tehnike ICP-MS, koje imaju mnoge prednosti nad ostalim analitičkim metodama: izrazito niske granice detekcije (Tablica 7), vrlo široko linearno područje (čak i do nekoliko stotina mg kg-1) te mogućnost simultanog određivanja velikog broja elemenata u istom uzorku. Nedostatak je visoka cijena instrumenata te visoki troškovi analize. Kao zaključak pregleda analitičkih metoda za određivanje teških metala na tekstilnim materijalima, iznesena je činjenica da se najbolji rezultati postižu kombinacijom različitih metoda odabranih i validiranih za namijenjenu svrhu

Analitičke metode za određivanje teških metala u tekstilnoj industriji

Heavy metals in textile wastewater represent a major environmental problem, and are a potential danger to human health when present on textiles. Furthermore, the presence of some metals influences the production of textiles. Heavy metals are often used as oxidizing agents, as metal complex dyes, dye stripping agents, fastness improvers, and finishers. Thus, they act as hazardous sources throughout entire textile processing. Toxic effects of heavy metals on humans are well documented. Therefore, it is important to monitor heavy metals throughout the entire production. Today, maximum permissible values for metals in textiles are given by different regulations, according to which the heavy metals have to be determined both qualitatively and quantitatively. Several analytical procedures for the determination of heavy metals were tested for their application on textiles. The advantages and disadvantages of TLC, UV-VIS, GF-AAS, ICP-OES, and ICP-MS methods are discussed.Teški metali u otpadnim vodama tekstilne industrije čine ogroman problem za okoliš, a kada se nalaze na tekstilnim materijalima iskazuju potencijalnu opasnost po ljudsko zdravlje. U tekstilnoj industriji teški se metali vrlo često rabe kao oksidansi, bojila te sredstva za poboljšavanje svojstava postojanosti. S obzirom na to da su toksični učinci teških metala na ljudsko zdravlje danas veoma dobro poznati (Tablica 1), vrlo je važno kontrolirati njihovu prisutnost tijekom proizvodnje i prerade tekstilnih materijala. Maksimalno dopuštene količine teških metala koje se nalaze na tekstilnim materijalima, pa se tijekom uporabe mogu ekstrahirati znojenjem i tako štetno utjecati na zdravlje ljudi, regulirane su različitim standardima (Tablica 2). Prema njima, potrebno je određivati i pratiti metale na materijalima, za što je moguće primijeniti nekoliko različitih analitičkih metoda. U ovom radu razmatrani su prednosti i nedostaci metoda TLC, UV-VIS, GF-AAS, ICP-OES i ICP-MS. Prije analize udjela teških metala na tekstilnim materijalima, uzorke je potrebno pripremiti za analizu. Velika važnost uzorkovanja (Slika 1), priprave i čuvanja uzoraka (tablice 3-4) naglašene su u poglavljima 2.1 - 2.3. Metoda tankoslojne kromatografije opisana u poglavlju 2.4. može se jednostavno i brzo primijeniti za učinkovito razdvajanje i dokazivanje različitih teških metala. Nedostatak te metode su visoke granice detekcije. UV-VIS spektroskopija je također jednostavna analitička metoda za određivanje metala koja zahtijeva pažljivu pripravu uzoraka. Karakteristike UV-VIS određivanja odabranih teških metala prikazane su u Tablici 5. Atomska apsorpcijska spektroskopija (FAAS i GF-AAS) jedna je od najviše upotrebljavanih metoda u analizi metala koja ima niske granice detekcije. Osnovni nedostatak te metode je nemogućnost istodobnog određivanja više elemenata u istom uzorku, kao što je to moguće kod induktivno spregnute plazme. Stoga je i priprava uzorka za analizu AAS-om dugotrajnija te iziskuje veće troškove. Zbog toga danas najprikladnije metode za analizu metala postaju upravo ICP-OES i tehnike ICP-MS, koje imaju mnoge prednosti nad ostalim analitičkim metodama: izrazito niske granice detekcije (Tablica 7), vrlo široko linearno područje (čak i do nekoliko stotina mg kg-1) te mogućnost simultanog određivanja velikog broja elemenata u istom uzorku. Nedostatak je visoka cijena instrumenata te visoki troškovi analize. Kao zaključak pregleda analitičkih metoda za određivanje teških metala na tekstilnim materijalima, iznesena je činjenica da se najbolji rezultati postižu kombinacijom različitih metoda odabranih i validiranih za namijenjenu svrhu

Interactive Effects of Large- and Small-Scale Sources of Feral Honey-Bees for Sunflower in the Argentine Pampas

Pollinators for animal pollinated crops can be provided by natural and semi-natural habitats, ranging from large vegetation remnants to small areas of non-crop land in an otherwise highly modified landscape. It is unknown, however, how different small- and large-scale habitat patches interact as pollinator sources. In the intensively managed Argentine Pampas, we studied the additive and interactive effects of large expanses (up to 2200 ha) of natural habitat, represented by untilled isolated “sierras”, and narrow (3–7 m wide) strips of semi-natural habitat, represented by field margins, as pollinator sources for sunflower (Helianthus annus). We estimated visitation rates by feral honey-bees, Apis mellifera, and native flower visitors (as a group) at 1, 5, 25, 50 and 100 m from a field margin in 17 sunflower fields 0–10 km distant from the nearest sierra. Honey-bees dominated the pollinator assemblage accounting for >90% of all visits to sunflower inflorescences. Honey-bee visitation was strongly affected by proximity to the sierras decreasing by about 70% in the most isolated fields. There was also a decline in honey-bee visitation with distance from the field margin, which was apparent with increasing field isolation, but undetected in fields nearby large expanses of natural habitat. The probability of observing a native visitor decreased with isolation from the sierras, but in other respects visitation by flower visitors other than honey-bees was mostly unaffected by the habitat factors assessed in this study. Overall, we found strong hierarchical and interactive effects between the study large and small-scale pollinator sources. These results emphasize the importance of preserving natural habitats and managing actively field verges in the absence of large remnants of natural habitat for improving pollinator services

P2Y13 receptors regulate microglial morphology, surveillance, and resting levels of interleukin 1β release

Microglia sense their environment using an array of membrane receptors. While P2Y12 receptors are known to play a key role in targeting directed motility of microglial processes to sites of damage where ATP/ADP is released, little is known about the role of P2Y13 , which transcriptome data suggest is the second most expressed neurotransmitter receptor in microglia. We show that, in patch-clamp recordings in acute brain slices from mice lacking P2Y13 receptors, the THIK-1 K+ current density evoked by ADP activating P2Y12 receptors was increased by ~50%. This increase suggested that the P2Y12 -dependent chemotaxis response should be potentiated; however, the time needed for P2Y12 -mediated convergence of microglial processes onto an ADP-filled pipette or to a laser ablation was longer in the P2Y13 KO. Anatomical analysis showed that the density of microglia was unchanged, but that they were less ramified with a shorter process length in the P2Y13 KO. Thus, chemotactic processes had to grow further and so arrived later at the target, and brain surveillance was reduced by ~30% in the knock-out. Blocking P2Y12 receptors in brain slices from P2Y13 KO mice did not affect surveillance, demonstrating that tonic activation of these high-affinity receptors is not needed for surveillance. Strikingly, baseline interleukin-1β release was increased fivefold while release evoked by LPS and ATP was not affected in the P2Y13 KO, and microglia in intact P2Y13 KO brains were not detectably activated. Thus, P2Y13 receptors play a role different from that of their close relative P2Y12 in regulating microglial morphology and function

Developing European conservation and mitigation tools for pollination services: approaches of the STEP (Status and Trends of European Pollinators) project

Pollinating insects form a key component of European biodiversity, and provide a vital ecosystem service to crops and wild plants. There is growing evidence of declines in both wild and domesticated pollinators, and parallel declines in plants relying upon them. The STEP project (Status and Trends of European Pollinators, 2010-2015, www.stepproject.net) is documenting critical elements in the nature and extent of these declines, examining key functional traits associated with pollination deficits, and developing a Red List for some European pollinator groups. Together these activities are laying the groundwork for future pollinator monitoring programmes. STEP is also assessing the relative importance of potential drivers of pollinator declines, including climate change, habitat loss and fragmentation, agrochemicals, pathogens, alien species, light pollution, and their interactions. We are measuring the ecological and economic impacts of declining pollinator services and floral resources, including effects on wild plant populations, crop production and human nutrition. STEP is reviewing existing and potential mitigation options, and providing novel tests of their effectiveness across Europe. Our work is building upon existing and newly developed datasets and models, complemented by spatially-replicated campaigns of field research to fill gaps in current knowledge. Findings are being integrated into a policy-relevant framework to create evidence-based decision support tools. STEP is establishing communication links to a wide range of stakeholders across Europe and beyond, including policy makers, beekeepers, farmers, academics and the general public. Taken together, the STEP research programme aims to improve our understanding of the nature, causes, consequences and potential mitigation of declines in pollination services at local, national, continental and global scales

Honey bee foraging distance depends on month and forage type

To investigate the distances at which honey bee foragers collect nectar and pollen, we analysed 5,484 decoded waggle dances made to natural forage sites to determine monthly foraging distance for each forage type. Firstly, we found significantly fewer overall dances made for pollen (16.8 %) than for non-pollen, presumably nectar (83.2 %; P < 2.2 × 10−23). When we analysed distance against month and forage type, there was a significant interaction between the two factors, which demonstrates that in some months, one forage type is collected at farther distances, but this would reverse in other months. Overall, these data suggest that distance, as a proxy for forage availability, is not significantly and consistently driven by need for one type of forage over the other

Methods for microbial DNA extraction from soil for PCR amplification

Amplification of DNA from soil is often inhibited by co-purified contaminants. A rapid, inexpensive, large-scale DNA extraction method involving minimal purification has been developed that is applicable to various soil types (1). DNA is also suitable for PCR amplification using various DNA targets. DNA was extracted from 100g of soil using direct lysis with glass beads and SDS followed by potassium acetate precipitation, polyethylene glycol precipitation, phenol extraction and isopropanol precipitation. This method was compared to other DNA extraction methods with regard to DNA purity and size

Ecological implications of a flower size/number trade-off in tropical forest trees

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